How to Resolve Conflicts between Husband and Wife in Islam
Question

A situation arose last week between myself, my wife and her daughter. Her daughter is now 20 years old with her own child but still resides in the home with us. I said something to my wife that made her upset with me so she became very foul-mouthed and ignorant with her behaviour even though there were no Muslims in the home. She approached me in an ill manner and I just lightly mushed her in the face and started laughing. The next thing I know she is punching me and kicking me. I grabbed her so she would not hit me in my face anymore, that's when her daughter got into it and started hitting me in the head. I Kept my head and did not become upset. Then her daughter called the police and they came and questioned everyone and took down a report. My wife has not shown any remorse about the behaviour of her daughter and acts as though it was ok for her child to act in that manner. At the present time I am not in the same house with them. And I really don't want to go back there. But I truly care a lot for my wife and try to strive with her in the way it is prescribed for us in the Quran and Sunnah. She only listens to the Quran and Sunnah when there is no anger in her heart. This is a situation that has left my heart weak. Living true Islam is all that I am striving for. Please assist me in this matter.
Praise be to Allah.Rights of husband and wife in Islam
It should be noted that one of the main reasons that cause problems between spouses , and that could cause these problems to escalate to a very bad level is a lack of knowledge of the rights which each partner has over the other.
Islam states these rights clearly , and urges and obliges each partner to fulfil them, as Allah says (interpretation of the meaning): {And they (women) have rights (over their husbands) similar (to those of their husbands) over them, but men have a degree (of responsibility) over them.} [Al-Baqarah 2:228]
This verse indicates that for every right that one partner has, there is a corresponding duty which the other partner must fulfil; thus balance will be achieved in all aspects of the relationship, which will strengthen the stability of family life. Ibn `Abbas (may Allah be pleased with them both) said concerning this verse: It is their (women’s) right to good companionship and proper treatment on the part of their husbands, and their duty to obey and do what their husbands tell them to do. Ibn Zayd  (may Allah have mercy on him) said: Fear Allah with regard to them (wives) just as they should fear Allah with regard to you. Al-Qurtubi  (may Allah have mercy on him) said: This verse covers all the rights and duties within marriage.
Overlooking trivial mistakes between spouses
One of those rights is that trivial mistakes should be overlooked, especially words and deeds by which no harm was intended. Anas ibn Malik (may Allah be pleased with him) reported that the Prophet (peace and blessings of Allah be upon him) said: Every son of Adam makes mistakes, and the best of those who make mistakes are those who repent. (Narrated by At-Tirmidhi, 2501 and Sahih Al-Jami, 4/171)
Avoiding Tit-for-Tat Reactions
Both husband and wife have to be patient and put up with one another, because everyone makes mistakes, and the one with whom you have to be most patient is the one with whom you live and interact with most. Neither party should resort to tit-for-tat reactions. If one spouse sees that the other is very angry, he or she should restrain his or her own anger, and not respond immediately. For this reason Abu Ad-Darda’ (may Allah be pleased with him) said to his wife: If you see me angry, calm me down, and if I see you angry, I will calm you down, otherwise it will be too difficult to live together. The Imam of Ahl As-Sunnah, Imam Ahmad (may Allah have mercy on him) married Abbasah bint Al-Mufaddal, the mother of his son Salih, and he used to say of her: Umm Salih lived with me for twenty years, and we never argued over the slightest thing.
Spouses guiding each other in faith
One of the most important rights/duties is that each spouse should advise and remind the other to obey Allah. It is reported in an authentic Hadith that a group of the Companions asked the Prophet (peace and blessings of Allah be upon him): Teach us which kind of wealth is best, so that we may try to acquire it? He said: The best is a remembering tongue (one that remembers Allah), a grateful heart and a believing wife who helps one's faith. (Narrated by Ahmad, 5/278; At-Tirmidhi, 3039 and Sahih Al-Jami`, 5231)
Balancing rights and duties between spouses
A man should avoid getting angry with his wife over something he dislikes, because if he dislikes one of her characteristics, he will like another, so he should balance the two. The Prophet (peace and blessings of Allah be upon him) said: “No believing man should hate a believing woman: if he dislikes one of her characteristics, he will like another.” (Narrated by Muslim, 36)
Samurah (may Allah be pleased with him) reported that the Prophet (peace and blessings of Allah be upon him) said: Woman was created from a rib, and if you try to straighten a rib you will break it, so deal with her gently. (Narrated by Ahmad, 5/8; Ibn Hibban, 1308 and Sahih Al-Jami`, 2/163)
One of the best ways to ensure a good atmosphere between husband and wife is a good attitude, hence Islam placed an important emphasis on this matter. The Prophet (peace and blessings of Allah be upon him) was the ultimate in good treatment of others and good attitude . 
Abu Ad-Darda’ (may Allah be pleased with him) reported that the Prophet (peace and blessings of Allah be upon him) said: “There is no good deed that will be put in the balance that will weigh heavier than a good attitude. The one who has a good attitude will reach, because of it, the level of those who fast and pray.” (Narrated by At-Tirmidhi, 2003 and Abu Dawud, 4799). 
Abu Hurayrah (may Allah be pleased with him) reported that the Prophet (peace and blessings of Allah be upon him) said: “The most perfect of the believers in faith are the best in attitude, and the best of you are those who are best to their womenfolk. (Narrated by At-Tirmidhi, 1/217; Ahmad, 2/250 and As-Silsilah As-Sahihah, 284)
Some of the ways in which one can treat one's wife well are to turn a blind eye and not to pick on things, great or small, and not to rebuke or scold for every single incident, except in the case of duties towards Allah. This is how Allah guides us in the Quran, when He says (interpretation of the meaning): {and live with them (women) honourably. If you dislike them, it may be that you dislike a thing and Allah brings through it a great deal of good.} [An-Nisa 4:19]. 
How to discipline a disobedient wife
If a woman disobeys her husband and refuses to obey him, he has the right to discipline her as prescribed by Shari`ah. Allah says (interpretation of the meaning): {Men are the protectors and maintainers of women, because Allah has made one of them to excel the other, and because they (spend) to support them) from their means. Therefore the righteous women are devoutly obedient (to Allah and their husbands) and guard in the husbands absence what Allah orders them to guard (e.g., their chastity, their husband's property, etc.). As to those women on whose part you see ill-conduct, admonish them (first), (next) refuse to share their beds, (and last) beat them (lightly, if it is useful), but if they return to obedience, seek not against them means (of annoyance). Surely, Allah is Ever Most High, Most Great.} [An-Nisa’ 4:34]
This verse indicates that the husband has the right to discipline his wife when she disobeys his orders or rebels against him, and that this discipline takes a step-by-step approach which may reach the level of hitting, within certain conditions.
Al-Qurtubi (may Allah have mercy on him) said: “Know that Allah does not command hitting in His Book in clear terms except in this passage and with regard to the prescribed punishments (hudood), so disobedience to husbands is equated with major sins, and Allah has given the task (of disciplining) to husbands, instead of leaders, and without the need for judges, witnesses or evidence, because Allah has entrusted wives to their husbands.”
Ill-conduct (Nushuz) here refers to disobedience, i.e., those on whose part you fear disobedience and rejection of the command of Allahto obey their husbands. Allah has made this discipline in stages, as follows:

Admonition without forsaking them (refusing to share their beds) or hitting them. So the woman is reminded of her duty to be a good companion and treat her husband properly . If gentle admonition and kindly reminders do not work, then the discipline is taken to the second stage:
Forsaking, by turning his back on her in bed or sleeping in a separate bed. But he should not go to extremes in this by keeping away for more than four months, which is the period set by Allah for the one that swears not to approach his wife. This forsaking should only be for the purposes of disciplining and correcting, not for taking revenge or punishing.
Hitting in a manner that is not painful , because Allah says (interpretation of the meaning): {beat them (lightly, if it is useful)}

Ibn `Abbas (may Allah be pleased with him) said: Forsake her in her bed, and if she mends her ways (this is good), but if not, then Allah has given permission for you to hit her in a way that is not painful. The husband must be careful to ensure that his hitting is for the purpose of discipline and warning, and not for any other purpose, so he must make sure that he hits as lightly as possible, by prodding with the fist and so on. Ata said: I said to Ibn Abbas: What is the hitting that is not painful? He said, The Siwak (tooth-stick) and so on. (i.e., hitting with the Siwak).
The Prophet (peace and blessings of Allah be upon him) said, advising his Ummah: “Fear Allah with regard to women, for you have taken them as a trust from Allah and they are lawful to you by the word of Allah. Your rights over them are that they should not allow anyone to sit on your beds whom you dislike, so if they do that then hit them in a way that is not painful. 
The husband should avoid hitting parts of the body that are sensitive, such as the head and stomach, and the face, because the Prophet (peace and blessings of Allah be upon him) forbade hitting the face in general. Mu`awiyah ibn Haydah (may Allah be pleased with him) said: I said, O Messenger of Allah, what are the rights of the wife of any one of us over us? He said, That you feed her as you feed yourself and clothe her as you clothe yourself, and that you do not say: May Allah make your face ugly or hit her i.e., in the face. (Narrated by Abu Dawud, 2/244; Ibn Majah, 1850 and Ahmad, 4/446)
If she desists, and stops rebelling, then he is not allowed to keep punishing her or to accuse her of saying or doing anything, as Allah says (interpretation of the meaning): {but if they return to obedience, seek not against them means (of annoyance).}
How to resolve conflict between husband and wife in Islam
With regard to your particular situation, we do not know all the details or the reason why you hit your wife or why she and her daughter attacked you. But we do understand that you are the one who started it, you started by hitting her then you made her angry by laughing at her, which is when the mistake on her part and that of her daughter occurred. 
What we advise you to do is to let your wife come back to you and go back to living together in one home.
You should advise your wife to admit that she has made a mistake, and explain to her the seriousness of what she has done by disobeying you, hitting you back and encouraging her daughter to misbehave towards you as you mentioned. 
This girl must understand that she is a guest in the home of her mother’s husband and she has to respect the one who has given her refuge in his home.
If her presence is making things more complicated and causing more problems, then you must come to some agreement with them for the girl to move to her own home. 
Seek the help of Allah, have patience and treat your wife well. We ask Allah to help you all and create love between your hearts. May Allah bless our Prophet Muhammad.
And Allah knows best.