Elisewin - first thing i would check is if the state you or they live in require that the child be responsible for the aging parent.

After that, i would say to be aware of your feelings. My mother was in the hospital a couple of times while i was no contact, and i kept having this idea that if i approached her, she would knock my eyeglasses off and break them, and i would be unable to drive myself home. A catastrophe. So i protected myself and stayed away. I am not one to indulge in such fantasies as a matter of course, but i figure my brain was trying to tell me something!

There are a lot of books and articles about going no-contact that you may find helpful.