I do have the opposite problem where DD works too hard. And I do think it's a problem, as I'm well aware other DCs will do equally well with half the amount of revision. But she does stop by 6/7pm, and we have been out most evenings (meals, cinema, table tennis, etc) so fingers crossed that her down time has been enough. She feels better revising so hard, so I am trying not to interfere.
No time really to get a proper job this summer. She has two different weeks of work experience, then a school concert tour of Eastern Europe, followed by our summer holiday which is over two weeks. She also has some trips planned with friends.
She is hoping to pick up some tutoring work in her A level subjects though. She is very strong in languages, and is going to look to tutor younger children in her own, and some other, schools. That should provide some money/independence over the next couple of years.
She hasn't really had a break (her choice) since revising over Christmas for her mocks, so I am loathe to push her to get any other type of paid work.
Good luck to all DCs tomorrow. History here.