You're fine, don't overthink it.
If you'd like more confidence, try to get 20-25 hrs in with a non-related general dentist, but the main thing adcoms look for is exposure to the profession so that you know what you're getting into.
I'd argue actually that shadowing a relative can potentially be a better way to explore the profession than shadowing a non-relative - relatives are more likely to be open/honest with you, talk about the harder aspects such as staff management, financial considerations, etc.