I think this is what they call a retorical question but if you knew someone who had a boyfriend who had a pregnant ex and she knew he was neglecting the baby after it's birth to be with her but there would be no way for their relationship to work if he didn't. But then it turned out he hadn't actually split up properly with his ex and he was letting the relationship drift apart but she didn't get it and felt mistreated would you think better of the woman you knew if she stayed with her boyfriend or if she left him after she found out the real situation with his ex?
I think I would think better of her and him as well if she stayed with him because that would show they really were in love and they weren't causing harm for no reason.