Because your daughter exhibits these behaviors only at school, it doesn’t sound like ADHD.
She may have a learning disability, have a problem with bullying or other peer stress, or be responding to family stress.
Start by asking for a meeting with the teacher, school psychologist/counselor, and others who know your daughter. Discuss what is happening and work with a team to put a plan in place. If these efforts are not successful, or if the school refuses your meeting request, speak with your family doctor about having her seen by a mental health professional.
Your daughter is showing that she is hurting emotionally. You must not wait to find out why.