I dont' know much about adopting an older pup but I wanted to welcome you to YT. But i would go with your gut. Did the place seem nice? The dog seemed friendly and not timid? Do you know why she is adopting her out at this age as opposed to keeping her? Does she look well taken care of?
How big is the dog? Hopefully all of the potty training issues will have already been taken care of for you
Good luck!