mlyn, I am so sorry. I was a caretaker to my mother as well as a daughter to her and it was difficult when she moved to get help. One piece of advice I can give you from personal experience is, yes you may not always be there physically but you can still remain close. I would call my mom and send her cards and little "thinking of you boxes" filled with things I baked. The best thing you can do for both of you is know and show one another, although you are apart physically you can remain together through other ways. Hang in there! And if you need to talk I'm all ears!
HUGS
Cher