If you are in the US (I'm not certain about UK), and provided your daughter is diagnosed (I'm assuming she is), you will need to get her hooked up with the disabilities office at the college. Once they have her paperwork, they can sort of set up a college level IEP and she can request the accomodations she'll need, such as extended time, computer use for taking notes, someone else to take notes, etc.. Once that's all done, the disbabilities office will inform each of her teachers through writing before class begins (also likely providing a brief description of what the diagnosis means and how they can help her in class) and what accomodations she is afforded.
If she's not registerted with a disabilities office, I doubt the professors will give her extra time. But provided she has a diagnosis, that shouldn't be a problem.