I ran into this when building a kids' education app a few years ago. We explored a bunch of options, from asking for the last four digits of their parents' SSN (which felt icky, even though it's just a partial number) to knowledge-based authentication (like security questions, but for parents).
Ultimately, we went with a COPPA-compliant verification service, but it added friction to the signup process.
It's a trade-off between security and user experience, and there's no perfect solution, unfortunately.
I ran into this when building a kids' education app a few years ago. We explored a bunch of options, from asking for the last four digits of their parents' SSN (which felt icky, even though it's just a partial number) to knowledge-based authentication (like security questions, but for parents).
Ultimately, we went with a COPPA-compliant verification service, but it added friction to the signup process.
It's a trade-off between security and user experience, and there's no perfect solution, unfortunately.