Don't let her reaction get to you - although it sounds like you aren't. It was probably somewhat unbalancing for her to not be invited right away, and she may have felt you invited her as an afterthought. I'm pretty sure this was part of Coach's plan though, so don't run in to fix it.
You are correct - I am not letting anything she does/doesn't affect me. And, there is nothing to fix with ME, so "If it ain't broke...."
