I can sympathise - this is much the same reason we are home educating. I hope your daughter is recovering.
It sounds like you already know this, but I'll write it anyway as it's so important - there is no deadline to learning. One of my aunts was ill a lot all through her school years and left at 16 without qualifications. She did what she needed all later, bit by bit in the evenings after work, eventually taking a degree and becoming a teacher. So anything is possible.
My children have approached exams with a mix of strategies. Some subjects have been studied entirely independently by buying textbooks and workbooks. Some subjects by correspondance courses. Some from online learning providers, even before Covid. And some were in group lessons (but that have switched to zoom since the first lockdown).
It really depends if there are any subjects you or someone else in the family feels confident helping with if you want to try with books alone (the main advantage of that is it's the cheapest way but it also means you can learn at entirely your own pace - you're not forced to complete tasks before the next online lesson). I'm good at maths and there's no nuance when comparing your daughter's answers to what's in the back of the book, so it's fairly straight forward (or at least I think so).
For English, we used a correspondance course with Catherine Mooney (www.catherinemooneytutoring.co.uk/) as she had been recommended by other home educators we know. Her courses are quite structured, in terms of what order you do things in, but you can work at your own pace.
Like you, we are spreading out exams - in fact, we are in the middle of the January sitting for science IGCSEs now. My son went to group lessons for those, as the tutor had access to more scientific equipment than we had at home. However, I'm not sure it's worth making a reccommendation for something you can't access now even if we were in the same area.
If your daughter is interested in computer science, my son really enjoyed the online lessons with Learntec (learntec.co.uk/).
Others have already suggested looking at the wiki pages (he-exams.wikia.org/wiki/HE_Exams_Wiki) and that's good advice. I found it really helpful. There's a lot of information to get your head around, so make yourself a cup of tea for your first browse and go back to it more than once if you need to.
Looking for a local home ed facebook group would also be a good idea as they will be the people who may know which of the exam centres locally are still taking private candidates as well as letting you know if there are any local tutors or group lessons.
Best of luck.