I was homeschooled (and very grateful for it), and mom was NOT my teacher. She would organize a lot of things like extracurriculars (mostly for socialization), but the studying I did by myself. She’d tell me where to read and do exercises in the books, and that’s it. And the testing in the end of the quarter would be done by a teacher in the school I was assigned to.

That’s what co-ops are for. We had one day a week where various parents would teach on their specialty, like theatre, biology, writing, music, etc.