If I understand right, your daughter has a Level 2 English qualification (GCSE grade 4) but does not have a Level 2 Maths qualification. She has taken the GCSE but scored a grade 1, and then she took a functional skills qualification but did not complete it. Now she is looking at taking a college course and because she doesn’t have the Level 2 maths qualification, they want to do some sort of assessment?
(I’m recapping because if that’s completely wrong, then the rest of my answer will be nonsense.)
I’d say the first thing is to check with the college to see what the purpose of the assessment is: is it because your daughter will need to meet a minimum standard to join the course? Or is it because they need to make sure she is supported while taking the course and they need to know what extra tuition she may need – perhaps they will even support her to complete a Level 2 Maths qualification alongside the course. If this is the case, you don’t really need to do anything.
Alternatively, if she needs to meet a minimum standard to join the course then she will need to study to improve her chances of passing the assessment, which I think is where you’re coming from. If this is the case, some options are: textbooks, websites, youtube videos, hire a local or online tutor for 1-to-1 training or take another functional skills course, whether in person or online.