sandwiches77
My suggestion would be to focus on the self-care first. She should aim to get up, shower and get dressed every day. She needs to eat regular meals and establish a healthy sleep routine. Ideally, it would be good if she can get out of the house at least once each day. Once her self-care is in place, hopefully she will be in a better place to start studying.
This approach worked for DS1 when he was unwell, and helped him to get through his GCSE and A-level years. He didn't achieve the grades he would have been capable of if he had been feeling 100%, but he did achieve enough to get into a good university, and he now finds university life easier to manage than school.