Well, it doesn't have to be a confrontation you know, and the fact that she's acting like nothing even happened, detached if you will in a way will work in your favour here.
Don't come at her with an accusatory tone or whatever,just say to her,
look such and such, I know we havn't always seen eye to eye, but I am concerned about something,
would you mind if we can maybe go somewhere private and have a little chat? *insert reassuring hand on shoulder here*
sit down next to her for a second, look her in the eyes, and then take hold of her closest hand and hold it firmly.
Say, I understand that, before the accident, you may not have been entirely thrilled with the pregnancy to begin with, and I have to ask
if there was anything, any reason preventing you from making the arrangements that would have been best for you?
Maybe throw in: we're family, and you can talk to me, at the end there if you're worried she'll jump on the defensive,
Whatever you say, you want her to percieve you approaching the issue with her, not you approaching her and opposing her with the issue.
Then you'll know if she was just a bit fragile dealing with depression, and being pressured into continuing a pregnancy she didn't actually want but never managed to work up the courage or self assurance to stand up for herself, then when the time was so close to actually having the baby she was forced to finally assert the problem and wasn't left with many option. Or... if her thought patterns aren't running coherently and she is acting without thinking lacking compassion for other people involved, etc and like you say is crazy and a possible danger to your neices and nephews. Or... something else entirely.
