At what age do you think kids can brush their teeth on their own, well enough so that they don't need to be checked by an adult afterwards?

My LO is 4.5 and we still brush her teeth for her, she actually won't brush her own for more than a few seconds. The funny thing is though, she is SUPER picky about us brushing her teeth long/good enough. I really want her to start brushing a good portion on her own and then we just do a quick check after and eventually do it on her own. Hopefully sooner rather than later?