I reckon Kay, a mother, was totally irresponsible to leave the children in the unholy and evil environment because she wanted to escape from the abortion of her marriage
Kay said she was going to take the kids--she wanted them. Michael could have physically stopped her. She would have gone to court to gain custody in a divorce. US courts almost always grant custody to the mother. But she made a fatal mistake in hurling at Michael that she had an abortion. Abortions were illegal in the US at that time. Her abortion would have been enough for Michael's lawyers to make the case that she was an "unfit mother" under the law.
I've speculated before that Kay could not have known for sure that she was carrying a boy--amneocentesis was unknown in the US at that time, and her pregnancy was only 3 months along. I think she was trying to be cruel to Michael in shouting at Michael that "it was a boy!"
