those people with whom nikaah is not permissible

Being married to a woman and her niece at the same time

Q: I want to marry my wife's niece who is 25 years old. I am 35 years old. I know that I cannot have both at the same time, but I have heard that one can marry another woman without giving divorce if he and his current wife have mutual consent not to have any physical relations. Please tell me if I can marry my wife's niece as I stopped all physical relationship with my current wife.

Marrying a woman who was intimate with one's son

Q: I have contracted a second marriage secretly. When my first wife found out some months later I confessed and openly went to live with her. The family being very upset did not accept this, the reason being

1. She worked in our store.

2. My son claims to have been intimate with her. He took her out for coffee and kissed her and also wanted to marry her.

3. She had some bad reputation /drugs /drinking /men.

4. She has an illegitimate son.

She became Muslim without being forced. I divorced her to keep every one happy she went into a depression and left town tried committing suicide. I felt I should help her. Her mother and father asked me to assist. Taking me as her husband, I took her back in nikkah again secretly. I brought her back home but could not live with her because of my family. I promised to take care of her. Is my intention and feeling to keep her due to the fact that I've seen her become a good woman? She now feels Islam is not just due to my actions. I've explained to her that due to the fact that she became Muslim all her passes sins would be forgiven, including my sons allegation that he slept with her which she deny's.

The question here is, is her slate cleaned as of her taking shahaadat or does her passed actions carry forward? In the event she slept with my son, she becomes haraam for me even though she slept with him prior to taking the shahaaada?

Can a person marry the daughter of the woman whom he committed zina with?

Q: My question is it permissible to have nikah with girl with whose mother I did zina? Now the story is that I did zina with a woman but the reality is that the woman did zina with me because I was 14 and she had three daughters at that time. Now my family did my nikah with her older daughter, she loves me and I love her and we happy for one another. I already did tawbah for what I did and I ask for forgiveness from Allah Almighty. Now we are in relationship already in nikah but I have a question sometimes in my mind, so is it allowed in Islam that her daughter be my lawful wife or I have to leave her? The zina one time we did almost 12 years passed, after that I never tried to do that with her mother nor her mother tried with me. Kindly answer me with details and references.

Can a girl marry her foster brother?

Q: My question is my sister who is in love with her khala's son but the problem in their marriage is that once she was crying in childhood so her khala made her drink milk from her own, so we consulted many Maulanas. They rejected their marriage. So we then approached to Jamie (bhatkal) they suggested it is possible in the Shaafi'ee mazhab but not in the Hanafi Mazhab and we belong to the Hanafi Mazhab and the main problem is they are madly in love. Please suggest me solution as early as possible.