nevermore,
Good luck to your daughter--I hope she feels better soon.
When I am already enormously stressed she can still get to me. I guess we never stop thinking they will act like a real mother during times when you need them the most. Never ever ever going to happen. :'(
I know what you mean. It doesn't make sense sometimes, does it? Even as adults, sometimes we want that unconditional love that most parents show their children.
zone out has a good point: do you think your mother would be ok with keeping the calls short? Maybe you could set a limit at the beginning of the call. I've done that with my mother with some success: "Mom, I know we need to talk, but right now we can only talk for 5 minutes." I've found that not giving a reason, but reaffirming that limit, has worked best.
Take care of yourself and your daughter.