I agree with- Sheila - it will be okay.
But I also can relate to your butterflies!!! I think that's normal with- any kid, just heightened with a difficult child. I hope she has a fabulous time (and that the troop leaders get the girls to bed at a decent hour, LOL).
Bravo to you for letting her go away for a week this summer!!! I'm a big believer in overnight summer camps - I think it's a fabulous opportunity for our kids to grow and learn. (Not such a big fan of the stress it puts on Mom, but that's a whole 'nother issue
).
I hope she has a wonderful time this weekend, comes home with lots of stories about what they did, and isn't too tired.