If my brother's wife raised me until I grew up, does she become a mahram (a relative one may not marry) to me?

Question:
One of the listeners says: I am a young man, twenty-two years old. I lived with my older brother and his wife after my father passed away and my mother married another man. My brother took me in when I was three years old, and he and his wife raised me until I reached this age, praise be to Allah. The question is: Is it permissible for me to greet my brother's wife or sit with her without being alone with her? What is the ruling on shaking hands with her? Please note that she is of my mother's age and has children who are close to my age. Do I consider her a close relative? Please advise us. May Allah reward you with good.

Answer:
Your brother's wife is a stranger to you, but she did well in raising you when you were young, so she has a reward, if Allah wills. You, too, should be dutiful to her and treat her well. As for the issue of her being one of your mahram (relatives one may not marry), she is not; she is not one of your mahram. She is required to observe hijab (the covering prescribed for women), and it is not permissible for you to be alone with her or to shake her hand. Rather, you must consider her a stranger woman, not one of your mahram. As for being kind to her and rewarding her for what she did for you, that is a matter up to you, and you are required to respond to kindness with kindness. However, it is not kindness to consider her a mahram to you. Yes.