when my dcs have asked how old you have to be to have sleepovers I've generally said they have to be much older than they are most likely not until teenagers. Now I've just been approached by mum to ds best friend who is planning sleepover for his 6th birthday with a handful of close friends. All boys. All Year 1. My ds is still 5. Mum is lovely, but I'm not sure she realises what she's taking on. I fear total carnage with a group of half a dozen 5/6year olds all getting high on party junk food and excitement. It can be crazy enough when just 2 of them get together for a playdate. My instinctive reaction was to say NO WAY! Far too young. But now beginning to wonder whether I'm being over-protective and party-pooper. I haven't replied to the invitation yet.
My DS has just had his first sleepover at 5 and a half. It was at one of his friends' houses, who he has known since he was a baby. I have known the Mum that long too so felt comfortable. However, my friend's daughter doesn't feel comfortable about staying at our house as she wants to be with her Mum, no right or wrong IMO they are all so different, go with your instinct.