R.Y.
My son is the same age and is his second year of preschool. Last year he was having pee accidents and not telling anyone (his teachers and sometimes me when I picked him up). I talked to his teacher and she helped by making sure he always had a turn when the class had a potty break. His school is good about having the kids all use the potty between activities (after lunch and snack time usually). I'd see what the schedule is like in school and see if the teachers can help remind her at least every two hours. Also, full days may just be making her very tired by the end of the day. Is she having the accidents late in the day? My son is tired when I pick him up at 12:45 (he has about 4 hours at school, 5 days). He also now goes to be much earlier than when he was 3 and still took a nap.