I don't think the tripod was MS filming herself for YouTube or other social.
she wasn't supposed to have the secret YouTube, at least my understanding of it. So she probably took short videos of herself and/or her friends did when they were together. I don't see a tripod as something the average 12 year-old would have, especially not one who doesn't even have her own room.

Kids film really short snippets of content, usually. At least mine do, and their other kids I have been around during their activities in recent years. Some of the stuff I was happily shown by the younger ones was really silly. Like making their cat dance for 10 seconds, or talking about why the iced coffee at ___ company was THE BEST. Or picking a flower, because they thought it was artistic. Not stuff you really need a tripod set up to film lol.
I would see it more likely MS filmed "shorts", or similar to things you might see on TikTok.
Pervert was almost CERTAINLY filming her in the living room. Probably filming the whole damn house, and claiming he was a "filmmaker" or some damn BS.