I disagree with your point about OT being "a very academic degree". While I would hope that any UK degree is academically rigorous, an OT degree is much more practice focused than a highly abstract subject such as mathematics. OT also requires a real range of skills and personal characteristics aside from academic ability to be a successful practitioner. I have (unfortunately) quite a bit of experience with dealing with OTs, and yes, the best ones are bright, but they also bring other skills such as empathy, care, good communication and excellent observational and problem solving skills.
I just found this overview of requirements for the OT Bachelor of Science undergrad degree at Lancaster and as you can see, the minimum GCSEs are 5 Cs, and 120 points at A-Level OR a BTEC DD (and Liverpool Uni has even more flexible entry requirements):
Minimum qualifications:
120 at A2 including Biology or PE or Psychology or Human Biology or Sociology
BTEC Extended Diploma: DDM in Health and Social Care
BTEC Diploma: D D in Health and social care
Pass Access Course: 120 UCAS points including 30 level 3 credits at Distinction
International Baccalaureate Diploma: Pass including 120 points from Higher Level Subjects
T Level Health: M
IELTS: 7.0 with no Component lower than 6.5
GCSEs: 5 at grade C/4 including Maths, English, Science/Health & Social Care
A satisfactory Criminal records declaration (DBS/Disclosure Scotland) and Occupational Health clearance are required for this course.
However, all of these courses require students pass a medical/OT screening, so it's really important that OP and her daughter understand if this is possible in light of any continuing or recurring health issues.
@Getbackinyourlane12 I think what your MIL said was terrible. I had a similar experience with my son and mother (I was not present, but my son was extraordinarily upset after a visit with her - he said nothing about it while with her). She totally dismissed his ambition while nodding along encouraging the hopes and dreams of the other children involved in the conversation. I know the children very well, and I am fairly confident that my child's chance of being an Olympic snowboarder is actually higher (even though a massive longshot and very very unlikely) than of the other child becoming a vet. The child in question has quite poor academic abilities, which could well improve with intensive academic support, but this is not forthcoming from the adults in her life. Being fond of horses is unfortunately not enough to get you on a Veterinary degree. Anyway, the upshot is that this has caused real damage to the relationship, and he does not view his grandmother in the same way anymore. He still loves her, but does not feel as 'safe' with her as previously if that makes sense.
As you can see from the Minimum Requirements bit above, there are many ways to get on an OT degree, and the academic requirements are what I would call solid rather than stellar. They are looking for a whole package of skills and attributes, and early SATs results are not the sole indicator of whether or not these skills and attributes are present at time of application. If your daughter is only 11 she still has plenty of time to make up for a patchy primary education, but you as parents will need to be on top of making sure this happens as well as getting any reasonable adjustments in place at school/for assessments incase these are needed on the basis of any continuing health or additional needs.
Good luck to you and your daughter!