Livid with teacher

My daughter is autistic and in year 6. Yesterday 10 mins after lunch she said she felt her period and didn't have a pad on. She asked the teacher if she could go to the toilet and was told no she would have to wait until home time. My daughter said she whispered to her that she didn't have a pad on and it was a female reason. The teacher said she didn't need to know that and she should have dealt with it in her lunch break. She had to go back to her seat and bled all over her chair.