I feel that if she doesn't have his last name it would make things a bit easier of her understanding that he is not in her life. Almost non existent. She won't have that constant reminder. Having his last name will remind her of a person who does not care she exist. Therefore, my point regarding confusion...
For future post try to keep it black and white. You never know that persons pain. Calling them out on what YOU think is right or wrong, is uncalled for. Kindness goes a long way.

