Legal Question in Family Law in California

That's a pretty complicated issue. For better or worse, Family Court judges see themselves much more as Solomons than enforcers of the law in most cases. So the first issue is going to be whether the braces were necessary or purely cosmetic. If they were purely cosmetic, then you have a good case for not paying for something not agreed on. If they were necessary, it gets very complicated, including issues such as the reasonableness of the amount (you can't be charged for titanium robotic braces when regular ones would do, without consultation and agreement), payment arrangements, and timing of the request. A parent only has 30-days to notify the other parent of a request for reimbursement for necessary expenses. So you have to decide whether to bother with an OSC re: contempt, which is a longshot but puts you on the offensive, or just wait until they go to court and ask for reimbursement.