D.R.
My daughter is 3 1/2 and suck her thumb. The teacher she will have when she move up to the next class playfully told my daughter in my presence that she would not suck her thumb once she arrive in her class. I kindly spoke with her away from my daughter and told her that we would work together in helping her to stop but that by no means did I want her (teacher) to forcefully not allow my daughter to suck her thumb. Things like this should be addressed immediately to avoid confusion for the child/parent/teacher.