Hello Andrew,

I am a homeschooling College/University student myself that is a great question first off have you checked the available resources Khan Academy provides for home-schoolers? if so here is the link:

https://www.khanacademy.org/resources/parents-mentors-1/homeschool-with-khan-academy/a/start-homeschooling-with-khan-academy 

Here you can ask questions and find support from other parents who are homeschooling.

As for you question this depends on your own vision of teaching each child works differently many students have there own level.

I hope the home-schooling resources can help you and your family.

Proud to be a Khan Academer

Katrina