3000 families. Probably a lot more than 3000 kids.

I'm sure they knew that he's a Nazi. I read an article from a watchdog blog about Mr. and Mrs. "Saxon" where there are some screenshots of comments where the wife goes on a bit about pushback and questioning of things the kids would say from their grandparents and other family. Considering that she is an immigrant I don't think it's far fetched to assume that the family she's referring to is Mr. Saxon's.

But that would mean the rest of the family themselves are not Nazis, and just trying to be able to maintain a relationship with their grandkids. That's gotta be a difficult thing to navigate. There's a very good chance they didn't know anything about the homeschooling group until the story broke.