It is completely inappropriate for her to set up counselling sessions for your children without discussing this with you. You are co-parenting and these decisions need to be made with that in mind. I think it's good that you called her on this but maybe stating that your concern is from a co-parenting perspective might have made the point without sounding fearful. Your fears about time with your kids being threatened are very normal. I refused to move from my home until I had a SA in place for that very reason. I told her "you've taken enough from me, I won't even take the smallest chance of losing my kids!" Anyway, I'd be curious to hear STBX's reply.