Related, Algorithm Watch has an active campaign about this issue https://algorithmwatch.org/en/stop-nudifying-deepfakes/

What can a person do about someone harassingly "twinning" their kid's likeness and internet avatar, if there is no proven loss or gain due to the intentionally fraudulent acts?

Start doing it to judges in your jurisdiction. It's a good way to seed the outcome of your own case in your favor.

Letting kids use social media is like letting McDonalds decide what their next meal should be.