So sorry you are having such troubles.
Re academic completion for this semester - maybe she can get incompletes for the D and F classes, so that she may complete work and study properly for finals at a later date which doesn’t sound like it is happening now. A mere C is so much better than D or F. Medical withdrawal should be available at any time for major problems, but any of this needs to be discussed with professors/academic advisor/advising dean etc. types at the college asap.
In many colleges it is too easy to be adrift due to large size and freedom of the students. Students are afraid to go to advisor or dean. If I was a professor and someone was getting D or F, I would have called them to office and tried to see what to do. However, I am not, and for many (most?) it is up to the student to seek out prof/advisor etc.
Even at large schools there are advisors and deans who are there to help those who are struggling. Even during finals and at the last minute. However, the student needs to go to see them before the failure.
As to all the issues contributing to the situation, these are for professional helpers. I think that seeking counseling for someone with a history of ADHD, depression, eating disorder, and other areas you mentioned would give a safe sounding board for all the problems and changes that she is experiencing.
Good luck.