I would say..its time for them to go. It is not worth the headache in this case. Your teacher is having to deal with stress she doesnt need...the other students probably are taking it all in and getting mixed messages about what is going on...it probably gets the other parents thinking and it could cause some more issues. It is hard as a teacher to be confronted about something which you have no control over and then have to go on to teach a class. No matter how hard it is so cover up your emotions it still effects you one way or another. I would rather have 2 students go then have 50 leave I feel for you and your situation...I was put in a similar situation last year...but the SO would not do anything to help me or help the situation so i left. I hope it works out for you! Stay strong!