Her father is addicted to alcohol and works for a Christian who sells pork; does she have to inform her suitor of that?
Question

I am a twenty-four-year-old woman and religiously committed, praise be to Allah. I have received a proposal of marriage from a young man who is of good character and religiously committed, and comes from a conservative and religiously committed family. When he asked about my father’s work, he was told that he is a butcher, but in fact he works as a butcher and salesman at the same time, for a foreign Christian man who sells pork and my father receives a wage for his work. In addition to that, my father is addicted to alcohol, something which tarnishes our honour and reputation. I am confused about my situation and I do not know whether I should tell my suitor frankly about these matters or not. If he asks me about them, how should I reply? Please note that I am not sure that he will marry me if he finds out the truth, and I want to get married so that I can live in a halaal manner after suffering a great deal because committing haraam things (in the past). I hope that you can advise me as to the right thing to do.
Praise be to Allah.We ask Allah, the Most Generous, to relieve you of the distress you find yourself in, and to make it easy for you to have a blessed marriage. 
Undoubtedly the marriage contract is one of the most important and significant contracts in a person’s life, because of the things that result from it that have an impact on the family and the community, and what the husband and wife hope for from it of a happy life, bonding with another family, and righteous offspring. 
It is important for anyone who wants to propose marriage to know about the family of his potential wife, and their reputation and standing. Based on that, the new marriage must be based on complete honesty and frankness, after which whatever Allah decrees will happen. 
If you father’s problem has to do with a private matter or a sin that he is concealing, then you do not have the right to expose him, or to mention that to the suitor. As for the issue of his work, if it is hidden at present, it will inevitably become known, and if he does not come to know of it from you, he will come to know of it from other people. 
Human relationships, if they are not based on honesty, frankness, sincerity and avoidance of deceit and treachery, quickly deteriorate, leading to negative consequences. 
Muslim (55) narrated from Tameem ad-Daari (may Allah be pleased with him) that the Prophet (blessings and peace of Allah be upon him) said: “Religion is sincerity.” We said: To whom? He said: “To Allah, to His Book, to His Messenger, and to the leaders of the Muslims and their common folk.” 
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) said: 
Allah, may He be glorified, has enjoined sincerity and transparency when dealing with others in particular, and in all other issues in general, and He has prohibited treachery, deceit and concealment.
End quote from al-Fataawa al-Kubra (6/150) 
What we advise you to do is inform your suitor about your father’s situation and his work, and tell him that you are keen to set him straight and advise him. If he does not respond, then there is no blame on you for that, so long as you are keen to do what is right and obey your Lord, and are adhering to the noblest of attitudes. The Sahaabah themselves were originally disbelievers, until Allah bestowed upon them the blessing of faith, yet despite that their fathers and mothers died in a state of disbelief; in some cases their fathers and mothers lived to see Islam, but did not believe in it. Allah, may He be exalted, says (interpretation of the meaning):
“No person earns any (sin) except against himself (only), and no bearer of burdens shall bear the burden of another”
[al-An‘aam 6:164]
“And no bearer of burdens shall bear another’s burden, and if one heavily laden calls another to (bear) his load, nothing of it will be lifted even though he be near of kin”
[Faatir 35:18]. 
Who knows? Perhaps your speaking frankly to him will prompt him to accept it, and increase the likelihood of love between you, so he will understand your situation and will appreciate your honesty with him and your desire to start the marriage on the right foot. 
Be gentle in telling him; you do not have to give all the details frankly and in full. Tell him that you would like to seek his help in dealing with this trial and that you would like him to help you to advise your father, exhort him and remind him. 
Whatever Allah has decreed for you in al-Lawh al-Mahfooz will happen. Allah, may He be exalted, says (interpretation of the meaning):
“No calamity befalls on the earth or in yourselves but is inscribed in the Book of Decrees (Al-Lawh Al-Mahfooz), before We bring it into existence. Verily, that is easy for Allah.
In order that you may not be sad over matters that you fail to get, nor rejoice because of that which has been given to you”
[al-Hadeed 57:22-23]. 
If what you want comes to pass, then praise be to Allah. If what you dislike happens, then perhaps you dislike something but it is good for you. 
And Allah knows best.