I have two dcs with various disabilities.
Ds has just had his final degree results and got a first. Dd is half way through her degree.
They have both struggled and neither has taken a straightforward route but they have both managed with support.
Ds fell to bits in his second year. He took a gap and picked up again in the second semester of the next year, having completed all the modules for the first semester. Unfortunately this didn't go well and he had to do the same again the next year. On his third attempt he finished 2nd year. At the end of third year he still had not completed all his modules so he took an extra year as an external student and managed to complete and to (just) get a first.
The disability services at his university advocated for him throughout. His department made accommodations for him but it was the advocacy from disability services which really made the difference. There was one person in particular whom he really connected with and he was happy to go to her when he needed support. I think this is key; having just one person the student is happy to connect with who is in turn happy to liaise with others.
Dd also came to grief in her second year. It was clear that she was not going to manage full-time study with her disabilities. Again with support from her mentor, disability services and her GP, she applied to study on part-time hours and the university allowed this. As she is doing a full-time course but on part-time hours as a reasonable adjustment for her disability she continues to be eligible for a full maintenance loan. Of course it will take nearly twice as long to complete her degree but it has made it manageable for her.
I am assuming that as she has already started her course and has a longterm condition , you have already accessed all the available support. However at the risk of overkill, I will just list all the things we have accessed in case it is helpful.
DSA - a good package of technology, mentoring, equipment. It is possible to go back and ask for additional things if they turn out to be needed. We did this for Ds.
The university's own disability services - they vary in what they provide but finding out what is available and being known to them is crucial. If the student agrees it is possible to arrange for a parent to contact them on the student's behalf. I did this quite a bit when Ds was in crisis. Although I have the same agreement for Dd, I have only had to do so a couple of times right at the beginning when she was still feeling her way.
PIP - if you don't already have it, it is worth thinking about applying. As well as having additional money to make life easier, it is a gateway to other help.
Social services direct payments- if your dc needs help with personal care or everyday living (cooking, shopping, laundry) you can ask for an assessment from social services (home address not university address). We got direct payments for Ds which meant he had a support worker for a few hours a week to help with practical stuff. It made all the difference to his coping in the last two years.
An understanding GP - university health services are used to dealing with student issues and dealing with the university. Dd's was excellent but it can be a bit of a lottery. Ds's were ok but no more than that although that was partly because Ds only engaged when he had to.
Charity or independent support organisations for the particular disability both nationally and any local services in the university town.
I hope that is helpful and encouraging. I am happy to answer any further questions.
Good luck to your Dd.