My girlfriend lived with her sister for the last few years of highschool, where she was claimed as a dependent the whole time they lived together. At 18, she was added to the lease. Her older sister then broke the lease to move into a small home, which she was unaware of. This all takes place in Arizona.

We were recently trying to move in together into an apartment, where she was denied and discovered this charge. Is there any recourse she can take? And if the only option is to pay it, even at a reduced payment, what would be the best method to go about that, considering neither of us have that much to spare as college students (ie. A loan of some kind, or a possible payment plan)?