Life changes in just an instant but it takes a very long time to get over things. Hopefully, she will pull through.
Your step daughters, sadly, are having to learn what us older folks have to and that's that life is fragile and you can never be fully prepared for what life gives you.

Seeing your child in pain or hanging on to life is something I can't even grip my mind on nor do I want to. I've heard so much bad news lately and hope for good news. i do believe that prayer makes a difference and she's got mine as do your daughters.