This story is very true unfortunately. If you had bothered to actually WATCH the movie you would have seen where she was told she was not supposed to be able to conceive a child. Also there are many women who just can't go through with an abortion whether it be religious reasons or personal convictions. Maybe she felt the baby is half her and she couldn't imagine if she were never able to conceive again and she killed the only chance she ever had. No matter what her reasons were, she did choose to keep the baby, not your place to judge. Not a 1950's choice either as they surely would have murdered the unborn baby.
She also did what she could to protect herself by moving away from him and taking private self defense classes. So if you don't like it that's fine. Just don't pretend you're God Almighty and only your opinion makes sense or matters.