It sounds like you have already asked her and got a perfunctory answer. Which is fine, just let that perfunctory answer be.
If it feels right, maybe wait four or five days and then invite her to the type of event or outing the two of you normally do.
It is a good thing to branch out socially and make new friends, even if you do have one special friend, and you don't say whether or not that was the case with her. But in either case, it's good to be open to new people, too. I think you may have read it correctly, that to some extent it may be jealousy on her part. Or, you may have neglected to practice host behavior or bridge behavior between her and other campers. And you may not even really have established skills in this area, which is fine. You're a human being, you certainly don't have to be perfectly. If you did make a mistake, just try and recover graceful and continue moving forward being friends with her if possible.