Ruling on preventing a non-Muslim grandmother from seeing her granddaughter
Question

                What is the ruling on preventing my husband’s mother, who is neither Christian nor Jewish, from spending time with my daughter? Please note that she has been treating us badly, and she is also a foreigner; she drinks alcohol sometimes, and she smokes hashish every day, and I am worried about letting her see my daughter. Please note also that my husband does not want his mother to see my daughter either, because he knows about her bad character.
Praise be to Allah.
      What we think and advise in such 
      situations is that you should adopt a moderate approach, because 
      moderation is the key to success in relationships between individuals and 
      societies, and it is one of the most important methods of modern 
      education, especially nowadays when there is a great deal of openness and 
      people are in close contact with one another because of means of social 
      communication. Therefore imposing restrictions and banning contact does 
      not lead to the desired results as much as a moderate approach may. 

    One of the most important ways of 
    achieving a moderate approach in this matter is to take into account the age 
    of the girl and the extent to which she will be influenced by her 
    grandmother. If she is very small, such as if she is an infant who is still 
    being nursed and the like, and she will hardly be affected by the attitudes 
    and character of people with whom she spends a short amount of time, then in 
    that case cutting off ties between the grandmother and her granddaughter 
    will not serve any purpose, and will only increase the rift between you and 
    her; this is not good, especially for her son who should honour her and 
    treat her kindly. But if your daughter has reached the age of discernment 
    and has started to learn from the people around her, then there is obviously 
    some risk in letting her visit her grandmother or spend lengthy periods of 
    time with her, without anyone to keep watch over her. In that case she may 
    see her when she is consuming intoxicants or smoking hashish, and curiosity 
    may motivate her to imitate her grandmother in these evil deeds, or at least 
    to wonder about how much pleasure she gets from consuming these things, 
    which may create in her an inclination towards sin and lead to a conflict in 
    her mind between the advice and religious practices of her parents, and what 
    she sees of sins committed lightly by her grandmother. In that case, nobody 
    can guarantee that the girl will follow the path of guidance, and no one has 
    the power to ward off whispers and bad thoughts in her mind; then there will 
    be the fear that the parents will bear some share of the burden of that sin, 
    because the child is a trust that is entrusted to the father, who is obliged 
    to protect and take care of that trust that Allah has given to him. A wise 
    man said: The best that parents may give to the children is praise, good 
    manners and righteous friends.

    See: al-Adab as-Sagheer wa’l-Adab al-Kabeer 
    (p. 34) 

    If you do decide to let your daughter 
    visit her grandmother, then that should be done in your presence or in the 
    presence of your husband, so that you will be safe from any kind of 
    influence on your daughter, and you can take her away from the place if any 
    harm or trouble arises, such as if the grandmother smokes near her, and the 
    like. 

    At the same time, all of this does not 
    mean that you should cut off ties completely with that woman; rather we 
    advise you to continue to keep in touch with her and treat her kindly, for 
    the Muslim should be a daa‘iyah (caller to Allah) in all situations, and he 
    should never despair of anyone being guided. It was narrated from Abu 
    Hurayrah (may Allah be pleased with him) that a man said: O Messenger of 
    Allah, I have relatives with whom I try to keep in touch, but they cut me 
    off. I treat them well, but they abuse me. I am patient and kind towards 
    them, but they insult me. He said: “If you are as you say, then it is as if 
    you are putting hot ashes in their mouths. Allah will continue to support 
    you as long as you continue to do that.” Narrated by Muslim (2558).

     Moreover, grandchildren are required to 
    honour their grandparents in general terms. Although parents are more 
    entitled to that honour, one should not cut off ties with the grandparents, 
    even if they are disbelievers; in fact they have the right to be honoured 
    and for ties with them to be upheld, commensurate with the degree of one’s 
    ties with them, because of the general meaning of the words of Allah, may He 
    be glorified and exalted (interpretation of the meaning):

    “But 
    if they (both) strive with you to make you join in worship with Me others 
    that of which you have no knowledge, then obey them not, but behave with 
    them in the world kindly, and follow the path of him who turns to Me in 
    repentance and in obedience. Then to Me will be your return, and I shall 
    tell you what you used to do”

    [Luqmaan 31:15]. 

    Shaykh Ibn ‘Uthaymeen (may Allah have 
    mercy on him) said: 

    The grandfather and grandmother have the 
    right to be honoured, but that is not equal to the honour that is due to 
    one’s mother and father, because the grandfather and grandmother did not 
    endure what the mother and father endured of exhaustion, care and 
    supervision. But honouring them is obligatory, and comes under the heading 
    of upholding ties of kinship. But the highest level of honouring is due to 
    the mother and father.

    End quote from Makaarim al-Akhlaaq 
    (p. 40) 

    And Allah knows best