Am I doing the right thing ?

Ok , long post warning , I am wife and mother to people with asc. My 16 yr old daughter is currently taking gcses , is very bright and able but in the past year has dropped off , refuses to attend school for whole days to avoid certain teachers/lessons. Attendance has impacted on her attainment but I believe there is also a part of her that is refusing to work for particular teachers , who she has decided arent worth her effort. She has been entered into foundation maths following her mock results after spending previous 4 years (with a different teacher) in highest math group . I have seen recent papers and she has not attempted 1 question . I and senco suggested She move to another math group , which she point blank refused to do. It feels like she is spiting herself and the teacher . This has happened before with other subjects and she has lost whole year of learning due to withdrawing her attention and making no effort after deciding the teacher was not good enough. School have offered her time in ls instead of going to lessons to try and ensure she attends the other lessons on those days but she is refusing to accept maths is the reason she is not going in. There is no problem according to her. 

I know , as in the past this has happened, she will talk in a few months or a year about how awful this maths lesson / teacher was and the reasons will come tumbling out. I also know it will be anxiety driven . Meeting it head on has not worked and strategies used so far are just driving a wedge between us. I am now resigned to backing off completely , which feels wrong but i do not want to be an additional cause of anxiety. My asc husband says to let her make the mistakes as he had to himself but i see how he has to work twice as hard as others to get to the same point . He can now accept a little help or support to make his life/job easier but for years had fixed ideas . It is so hard standing back ,, watching someone you love so dearly making mistakes which will shape the next few years of her life. 

Thank you for listening

Any advice would be welcome.