DD (Year 7, age 11) has been invited to birthday sleepover. I have never met the girl who's invited her. I've said that as I don't know the family at all, she can go for the afternoon and evening celebrations but she can't stay over (this time).
I think it's reasonable to what to know people at least a little bit before you let your child spend the night in a stranger's house. And that this is a useful precedent to set as she becomes older.
Unsurprisingly, DD is rather unimpressed with this view and DH also says I need to 'take a chill pill'. AIBU? WWYD?