If my daughter's private school prevents her from sitting any GCSEs could this be considered disability discrimination?

My daughter is Autistic and has ADHD, she has also struggled with OCD, anxiety and depression. She has an EHCP and attends a mainstream selective private school.
Unfortunately, due to her mental health, her attendance has been poor (under 50% in the last year.) However when she doesn't attend school, she has been working independently and with private tutors. She has made huge progress and her tutors feel that she is in a position to sit her GCSEs.

She has significant exam related anxiety, initially preventing her from even doing practice exam questions.
She was very anxious during her mock examinations, and was unwell during them but did attempt the mocks getting between a 5 and 1 (depending on how much of the paper she was able to attempt.) This has however increased her confidence to attempt questions and therefore sit the exams. We had an initial meeting during which my daughter explained that her plan A would be to attempt all her GCSEs if well enough, plan B would be to attempt some this year and plan C to sit none. Her school then asked her to sit a further history test as the mock (in which she achieved a 4) didn't cover all the content and she hadn't attended lesson. It was explained that she'd only be able to sit actual history GCSE if she did well in this additional test. Unfortunately, she was unable to sit the test (although she had worked hard to cover the content.) We have repeatedly explained that the uncertainty and pressure related to the thought of school stopping her sitting GCSEs has contributed to her struggling to attend. This was initially explicit, with my daughter being told that if her attendance dropped below 80% she would have to drop a GCSE - but following advice from an educational psychologist this was dropped.

We then had an email from school stating that they were going ahead with my daughter's plan B and allowing her to only sit maths, English language, a single science (or dual science foundation level.) They said they couldn't prevent her sitting English Literature as she has completed coursework to a high standard but advised against it. We requested that she be allowed to sit Latin, English literature, maths and biology and this was provisionally accepted via email.

We have then had a further meeting and explained that my daughter has accepted it is in her best interests to spread out her GCSEs but she needs clarity that she will be allowed to take them and she will not be withdrawn against her will. The deputy head initially said that this was not possible a they would make a risk assessment about the benefits and harms of her attempting the exams. We and my daughter pointed out the significant harms of not clarifying this, as the pressure/uncertainty would make it harder for her to attend/study. We suggested that the impact on her mental health should be determined by her mental health team and not school. At this point the SENCO explained that she'd only not be able to sit the exams if she was unwell and that there were benefits to being withdrawn rather than just not attending (as this would be classed as a fail.)

We went on to have a further difficult discussions with unhelpful remote interventions from her EHCP coordinator. This left my daughter very upset so we concluded the meeting.

I therefore I emailed following the meeting to follow up some things and confirm that my daughter would be allowed to sit her GCSEs unless her medical team felt she was too unwell.

School have thanked us for our email and said they will respond in due course.

I am very concerned about the impact this will have on my daughter. She has come to terms with the fact she can't sit all her GCSEs so has been focussing on intense practice for a smaller number of exams. She has always struggled with the additional pressure placed on her by school, with the implication she will not be able to sit the GCSEs she wants. In some ways, it was a relief when they limited her to 4 GCSEs as she felt they had no further power over her but now she feels this is not the case.

Can her school prevent her from taking exams she has been entered for based on arbitrary risk assessments without input from her, her family or medical team?

We are distraught that we have been paying significant amounts of money to a school which appears to actively harmed her mental health and academic prospects. (We kept her at the school as it was small, familiar and there did not appear to be any viable alternatives.)

School have put a lot of exam adjustments in place including an individual room, rest breaks and extra time. They have not given the option to sit exams at home. The deputy headmistress said this is definitely not possible but the SENCO explained that it could be possible but she is concerned about the impact on my daughter's feelings about home.