DD1 has had 1 sleep over with Nanna (i think) and that was within the last yr.
With DD2 it's been hard as she was BFing and a little funny to settle at night so that did affect my options of letting her stay somewhere, now though i would happily send her off for a sleepover with Nanna, SIL or to my cousins, i would also entrust her to you if the need ever arose

I'm at the point know where even though i know DD2 might be funny to get to sleep with someone else if i trusted they would do whats right for her, comfort her and wouldn't get angry with her not sleeping then i would probably still allow them to have her for a sleepover, but i wouldn't just hand her over to someone i thought might get frustrated IYKWIM.

Prob no help at all...