DD (11) has just started secondary school and has made a new best friend who has invited her for a birthday sleepover this weekend. I haven't met the girl or her parents and won't have the chance to do so before the weekend. I am not happy to say yes to the sleepover (usually say no to sleepovers in term time anyway) but have said DD can go to the birthday party and I will pick up in the evening. AIBU and over-protective or should I let my 11 yr old sleepover when I haven't met the parents or even the girl (who DD has known for all of 2 weeks) myself?