Have you talked to the teacher's supervisor? Be it the principal or team leader, or gt teacher at the school? It could be that the teacher is so overwhelmed with the new system that she ahsn't noticed the change. Or, it could be that there is something going on in her personal life that could be affecting her teaching.
Was she a 2nd grade teacher at ehr old school? If not the new age group could be the biggest problem for her.