Supporting during exams

My daughter (aged 17) is in her first year of 6th form and in the middle of "Mock" A-levels. She is clearly very able - despite missing a lot of school and with no special support she managed a good crop of G6-9 GCSEs. However, exams cause her HUGE anxiety (whether she will actually go to school on exam day is always a cause of anxiety for us) and her performance in maths and physics tests over the last year has generally been very poor overall. I'm trying to work out how to help my daughter achieve what I think she is capable of and what she needs to achieve to follow her chosen career in engineering. So I have two questions that I wonder if anyone can help with (and do feel free to refer me to any previous questions on this forum- the archive of which is quite daunting):

1. How do I help our daughter feel less anxious around exams. I recognise (and remember) that exam nerves are pretty normal, but in my daughter's case they seem to be paralysing. We have already secured her the right to sit her exams in a smaller room, with breaks and extra processing time so I really want to be able to help her with dealing with the excessive anxiety that prevents effective working before and during exams?

2. Understanding the impact of autism on my daughter's thought processes is a challenge, but it seems to me that she often struggles to recognise questions related to things she has been taught because they require application of knowledge from one situation to another. I don't think she is generally incapable of doing this - she is very good at doing puzzles or recognizing links between apparently unrelated things. In these situations she knows they are "games" and has no expectation of anyone having taught her the answer so doesn't expect to instantly know the answer. However, in the context of exams I think her immediate reaction is "we haven't been taught this" leading to panic. It's as if she doesn't understand that exam questions aren't just about recall but also about application and that if she could recognise when a question is a "puzzle" question rather than a "recall" question she would do a lot better?

Any suggestions on the above or anything else that might help me support my daughter through A-levels would be really welcome - I think she has the ability to follow her chosen career path, and it is heartbreaking watch her worry and fail