Hey Bunches, I think you need to be a bit less accommodating to her. Even though you are D she still seems to be cake eating.
Maybe you need to go back to DB principles and GAL. Ask her to look after S an extra night each week because you have a class to go to or something like that. Also rather than her coming to you to spend time with S suggest you drop S off to her and go out so she has no excuse to cut the visit short. Does she not have a place of her own?
I know it's hard not to know what is going on in their heads. I think sometimes we miss the signs but then are to cautious when we do notice them. It's a fine balance I think.
Me - 47 H - 45 D-16 M - 6 years Separated - May 16
Don't leave me behind can't you see me I'm shining... (Years & Years - 'Shine')