My daughter had an episode this year when she cried about going to school for a couple of days in a row, finally it clicked with me that something is wrong at school. I asked her a few questions, then I got to "is there anyone in the classroom that is picking on you?" This was it for her! There was a little boy in the class that had been bullying her, pushing her down, saying mean things to her, etc. Mostly all when the teacher wasn't looking. I went to the school and had a quick, private talk with the teacher. She took care of it right away. I didn't doubt that she was a good teacher, but she certainly reinforced it in my mind.
You definitely need to talk to your daughters teacher, esp about the using the bathroom thing. That just isn't ok, but the teacher may not realize the problem. Also sometimes what a sensitive little girl perceives as "mean" may not really be that mean. I'm just saying talk to the teacher.
at 9:57 PM on Nov. 12, 2009