Re-read the stuff on detaching. It really has nothing to do with physical proximity or amount of contact.

Not helping her out with the kids is not detaching, to me.

BTW you weren't catering to her, you were catering to your kids. Ask yourself, is it best for you kids to be in a situation with a sick parent?

I mean it's not like she was asking you to watch them so she could do out and party. This was really a no-brainer.

Patience is bitter, but its fruit is sweet.
--Jean Jacques Rousseau.