One of the things i do not understand is how is OWs relationship with your husband and as the teacher of your daughter acceptable on a professional level? Have you discussed this with your attorney? With the school? If this came out publicly it would not look good for a private school. In fact, this might even be your leverage if you had a lawyer so inclined. No one wants the embarrassment of a subpoena.
I think she has a bit too much power right now and she should not. I think they are intimidating you because they know that you really have a lot of power that you have yet to use. I don't think you should say anything, as vanilla says keep your cards close. But perhaps consulting with a more aggressive attorney as well? They are bullies and we all know that fighting the bully back works better then waiting for the teachers to make nice. It's the only way they can respect you and a 180 from a more passive approach.
Remember it's easy to climb back up when you have nothing left to lose.
Admittedly I myself am somewhat vengeful and I am not an enlightened person, (I am mostly cicilian after all ) so please I know what I would do at this point is probably not best advised. But could this help your custody case?
Again this is just an opinion and thought of one poster that is sick of seeing people being taken advantage of. I don't know if what I say would work in your favor. Just something to mull over and consult with a expensive attorney about.
Me: 42 H: 43 Twins age 5 Physically Separated 7/2015