You can contact your lawyer and take this to court with every other scrap of evidence that you have from the last few months to a year. You can also probably try to get a temp custody order and keep kiddo in her normal school. Jeez its what? a month until the end of semester? My brothers middle school has exams in three weeks. that is no bueno for kiddo.

If you can and if she causes a lot of other problems, I would weigh carefully the option of trying to take her to court for contempt for the changing the schools since it is a direct violation of the order. Also, so that you can continue to document a history of her not being able to follow a very specific court order (what you posted from the court order is pretty specific...I don't understand how some BMs can just ignore what is a law...it IS so frustrating).

In the future, if you have other problems, this kind of documentation could help. At the very least, send a certified letter with return receipt documenting that you learned this information, stating what the court order says and that your DH was not notified as per your court order. And ask her why she failed to follow the order and notify him in writing. Also the reasons you may disgree with her making the sole decision without notifying your DH as she is required.

I know how much it seems like a lose-lose situation. But you never know what she may do worse in the future and that kind of documentation of the history of her directly violating the order could potentially help. But we also learned that the part where DH is documenting his disagreement with such decisions and that he wasn't informed was important too and to show that he just didn't placate and that he was attempting to get her to follow specific orders.

In our situation, BM ignored the court order for 9 years. DH had it modified about 4 years ago and it was very detailed. She still ignored it. When she decided moved across country last year with two weeks notice and not informing DH per the court order, that allowed DH the opportunity to meet the requirements based on a significant change of circumstance to petition for a change in custody. Despite all the problems before not following the order, her changing schools without his consent, domestic violence at home, missing huge amounts of school, pulling ss out to homeschool him and never doing so...all without following the orders ...that was unfortunately was never enough to petition for a change. The move did allow him an "in" and that allowed him to show all of the documentation of her history of an inability to follow a court order to prove his case. We never thought he would be awarded custody after so many years. But he was! It took the kids having to be in some really bad situations where he couldn't do anything, many times of her violating the order directly and not being able to do a damn thing about it...that all played into him being awarded custody.

I always told DH to protect himself because we both knew she was nuts and very unstable and no one ever knew what the next crap was she was going to pull. So he documented everything just in case something major came along and he needed it...whether it was basic, documenting in a journal to remember dates and events, saving all emails and responses, and sure enough, it did eventually happen and all of that stuff made a huge impact when we never thought it would.

I think we also got lucky with a great attorney and a good judge who "got it."

Good luck!