Fairy Festival in Washington state - come join us!

Check the website, which will answer several of your questions and tell you much more. They'd probably not say they were wearing 'costumes' as much as bringing out their inner fairy/nature spirit.

It's been over a decade since I went, seemed to be maybe 40 people then? I expect it's grown, quite a few people giving talks there, which isn't why I go. Some are there for fun, some to learn. I absolutely felt something akin to 'nature spirits' when I was there. Just felt free and really connected to nature.

Yes, people camp, but again, check the website. I'm guessing if your daughters loved that movie, they'd love this gathering. But while there are kids there, it's not a kids festival. It's for all ages.