Other than her job prospects and getting to be in the DC scene, everything else points Case, especially the actual school. And do not underestimate the benefit of not being in class all day and of having pass/fail curriculum - those will probably do more for your quality of life than any city would.
Just considering your Cleveland cons, while I do imagine DC has the better job prospects for your SO (or at least more variety), just for the record as somebody who has lived in DC and Cleveland and is also a runner, the idea that Cleveland only has a couple safe places for that activity just isn't true at all. Both cities will offer more safe running paths than you'll probably ever use (especially if you include immediate suburbs, where public transportation in both cities will take you if you don't have a car).