change birthday for my kid's apple id

Hello,

I want to change the birthday for my kid's apple id. I set up their apple id with a bogus birthday. Now I want to set up family sharing. I set it up as me as the organizer. I added my two kids and they accepted. I tried to change their birthday in their Apple ID and it sent me an email. I clicked on the link. Logged into iTunes and verified my credit card number.

my kids still show up as Adult in my family sharing. Argghhh!

How do I make it recognize they are now kids?

Thanks,

gigfy