The New Woman

A man and a woman are sitting in a room. The man's mother-in-law and the woman's mother-in-law are mother and daughter respectively. How is the man related to the woman?

A woman is married for the second time. Her first husband was ABO blood type A, and her child by that marriage was type O. Her new husband is type B and their child is type AB. What is the woman's ABO genotype and blood type