Try to look for things that YOU can suggest that the family do together, so you don't have to respond to hers. It's fine (and good, actually) to continue to do family things together, but you don't want to look as if she's leading you around on a leash.
Come up with stuff, and then say "I'm going to take the kids to see that new guinea pig movie on Saturday; you're welcome to join us if you'd like" -- that sort of thing.
