Depends on the child’s maturity really for age 9. I recommend for smaller kids. But for cheaper you can just get the regular tablet for a 9 year old. Or if you can afford... the iPad. Just my opinion. But this tablet is great for younger kids. Or if you want to minister your child’s online screen time.
And with YouTube you have to approve each video that the child can watch and dl it to his account from yours. So for a nine year old you would have a lot of enabling of things to do. Hope I understand what I mean.