Nope I would go to the rental office. Unless she has the litter box close to the door, which I doubt, then they are possibly destroying that apartment, and honestly if she isn't home enough to change their box, they are probably suffering from neglect.
Most cats quit using their box when it gets nasty. So these kitties are probably destroying the carpeting. Ick.
In the meantime I would put some renuzit on the floor by her door.