Family accounts - yet again: How to add child account?

Greetings! I've succesfully created an F&F account and linked my pre-existing personal account to it. I would now like to add accounts for my children but it seems the only option is to create fully verified accounts in their name including legal identification, etc. That's not a problem, I'm just not sure whether I'm missing something and there is an option to just add an account under the master account that is not "fully verified", but just takes all the legal details from the family master account (such as beneficiary, etc.)

Edit to clarify: The kids are too young to need access to the account, I just want their investments separated, due to money inflow from grandparents, etc. I don't want that mixed with my investments.