I'm sympathetic to her insecurity, which is why I've mostly let this be, even though it means that sometimes it's hard to do ANYTHING with a group when she is there unless it is the thing she chose.
But I have tiptoed around this insecurity long enough. I need to ask her to grow up & get comfortable with the fact that sometimes there are people who are doing things that they'd enjoy doing, & it would be nice to let them enjoy doing them.