How can I reset the password to my child's account?

My children are unable to log into their accounts, and their accounts are linked with with mine in Family Safety. I am able to input all required information to identify their account in the account verification form, but they have not sent emails from their account. Every time I complete an account verification form, it tells me I haven't provided enough information. How can I provide more if they have never sent an email? It is VERY frustrating that as their mother, I am not able to help them reset their password and now their account and personal information is not within my control. Microsoft needs to fix this issue, I have read dozens of posts from frustrated parents about this.