Children with adhd/asd

My daughter is going through the process of assessments they are not sure what it is yet she is 6, today she came out of school and just showed me her finger with a plaster on I asked what happened and she said I peeled my finger. She didnt talk much and this is usually a sign she has had a hard day, so in the car home I asked if she wanted to talk about it and she shook her head, I then asked if I could ask 1 question she nodded so I said "did you do that to your finger because of what has happened today in school" and she nodded again. I left it there because when pressured she shuts of More or end up in an emotional state. When she showed me what had happened I couldn't believe it she has chewed basically the tops layers of her skin. All night she had been quiet and at dinner time she just burst into tears and came for a cuddle. So I ran her and bath and brushed her hair whilst in the bath she told me more, a boy in her class had shouted at her 8 times and she said it was at break time and she doesn't like when people shout at her, she just couldn't stop biting and had made it bleed! She does take something called a worry monster to school with her and has her own note pad so she can write down how she is feeling and put it in the monster throughout the day. Trouble is she didnt have access to this at break time. I dont really know what to do about this as I am managing the difficult or different behaviours at home but at school it's really hard. Has anyone got any advice on how I can make things easier for her when I'm not around?