I don't think it's actually you she doesn't trust, I think it's the fact that you'll be staying unsupervised with another adult without you're parent. I honestly don't blame her, I sorta wish my mom didn't let me go to some sleepovers when I was younger, as the adults are untrustworthy and your parents have no idea what could be happening to you.
You could always have your friends over to your house! That way, your mom knows your safe. Wait till you're a bit older to have sleepovers at other people houses and when you know right from wrong.
Good luck, and I still hope you're able to have fun with your friends! :)))
