Okay, some of your replies are pretty intense. She wasn't shunted off to a stranger, it was obviously a friend of the mothers, who she trusts with her own child, and has his own children, took her to a film. This other parent is not some random off a street. I have helped raise several of my friends kids, and have taken kids to the park or other activities in the course of this. I wonder if it was a female friend if you would have been more comfortable? Sure a text would be nice, but my first guess would be that this was just a spur of the moment extra activity? A film, with four kids all tagging along with one parent? Then a sleepover? Sounds like a rad night to me!
Secondly, she didn't sleep at a strangers house, the kids did an activity and then had a sleep over as planned.
In Australia kids can travel without car seats from 7 as long as they are not too small for the belts to fit them properly, then they need a booster. But otherwise, no problem. Not sure where the poster is.
I guess the rating of the film is a bit
but really - here are some examples of PG rated films, that reccomend guidance for kids under 15 - Home Alone, Harry Potter, Jumanji, How to Train Your Dragon, Beauty and the Beast. I bet HEAPS of parents are cool for their 8yo to watch these films alone even. Without knowing the specific film, I think YABU.
Pretty much, YABU. But if all this freaks you out, then def host yourself and yell at the other parent and kill off a few opportunities for your kid to socialise without you.
At most, I would get my kid to ask the parent to text me if plans change again, I wouldn't rush in with massive alarm bells ringing telling them to BEWARE every change in plans. Your dd is obvs big enough to let them know that, I would roll with it.