how do i separate a family shared card

There is no such thing as separating an account. You are the account owner and you may ask up to 5 additional people to become Participants. A Participant shares your account and has no legal responsibility to make payments etc. The complete details are in the first link I posted above.

The other way for your sons to open an account is to apply for an account and meeting the banks credit/risk requirements. If your sons have no credit history or the history is 6 months or less they are unlikely to be approved for a new account. Several banks offer student accounts and also offer secured accounts. After 6 to 12 months with a secured account, if in good standing, will transition to a regular credit card account and the deposit is returned. I would personally look at what Chase Bank offers and also Discover Card.

If your sons are 18+ they may apply for their own accounts. An alternative would be to invite them to be Participants (Authorized Users) and then they become part of your account.

Please review the support articles below and if you have additional questions or concerns, please post a reply.

Set up Apple Card Family and add a co-owner and participants - Apple Support

Build credit history for Apple Card Family participants - Apple Support

Set spending limits and get notifications for Apple Card Family participants - Apple Support

You’re welcome. I hope everything works out for your sons.