Mezonos Maven: They should ask a shaila about camp (or other) earnings. I believe the side that says not has a svorah that taking the money away from children who work to pay tuition teaches them that working hard doesn’t pay off (may have been a chinch roundtable, I don’t remember), which would apply here as well.
So the short answer is, all other things being equal, then yes. And I know of parents whose children work for the yeshiva (I believe) in lieu of tuition.