Brushing teeth

Okay, so this is still a big challenge for us. My LO wants to do it on her own and will NOT let us help. Obviously, she's not very good at it at this age.

Her teeth look okay, but I'm not really sure if we should continue to let her do it herself and teach her to improve her technique over time, or if we should intervene and force her to let us do it.

I've tried many different tooth brushes, including electric. She likes them all, but simple doesn't let us help. I don't want to make it a horrible experience for her, but I also care about her dental health.

Any tips? Any dental professionals out there?

What's the worst that could happen (I mean, they're just baby teeth after all)? Are there signs we should look for to determine if we need to take more aggressive action?

Thanks in advance!