I've come close to terming but never have but I did add a clause into my contract about possible reasons for termination and failure to adjust in a reasonable amount of time was one of them.
I agree with Judy. In most cases (but not all), it is something the parents are doing at home that we are not doing at dc that is causing the child to cry. I have made suggestions to the parents in the past and thankfully they were on board (because they didn't want to be kicked out lol) but if they weren't on board and the crying was going on for longer than a month, I would seriously consider terming. I just hate punishing the child when it's something the parents are clearly doing or not doing.