You have a difficult situation as your ex may not wish to comply or may not be able to comply no matter what you do. You can file a contempt charge against her for non-compliance with the court order, however this can be costly.
You can also call the school and show them the court order for joint legal custody (you can also do this with doctors etc.) and then they should be able to talk to you regarding what is going on with the children.
It sounds like it may be best to file a Request for Order to have full custody of the children and change their school, even though it seems that you do not want to do this. If they are not doing well in the current school environment and failing--a change may be better for them. If you don't take responsible action soon, you may have much bigger problems down the road.
Answered on Jan 29th, 2015 at 5:35 PM