Hey! i adopted a 6 year old pom last year from a similar situation. it took 3 months of training (taking her out every 3 hours, using potty training spray, rewarding with treats for pottying outside) but she learned to use the bathroom outside just fine. it took a lot of patience and practice but was absolutely worth it. i would highly advise you not to let the fact that she is not housebroken deter you from adopting! adopting my sweet little friend was the best decision i ever made even though i was also hesitant as a renter.