Child's Apple id has Mother's name and contact details associated with it.

We have family sharing set up for our family. Everyone has their own apple id and email. But for our son's apple id, his apple id name is his mother's and his contact details are his mothers.

If I go into his Contacts app and edit his card details will it also change my wife's contacts? Because it looks like it would.

How can I safely change his name from mom's to his name without making a big mess?

Each of them has their own apple id, but her name and contact details are the same as his for his account.