Assume she's not housebroken, that way if she is then you are pleasantly surprised. I would definitely get her a crate or kennel where she can have her own space. Also, it helps to keep the dogs separated while you aren't around to supervise. And that helps with potty training. I always try to make time in the evening for each dog to get individual attention. I would put my own dog away in the bedroom for 30-45 minutes and focus on the foster. As for new situations, keep things positive and keeps lots of treats on you at all times. One of our fosters did not like getting in and out of a car but I used treats to lure her into the car and the short car rides were always good because we ended up some place fun like the dog park or out a walk somewhere new.

There is almost always an adoption fee. The places that house unwanted animals have to make money to feed them, shelter them, give them meds, doc visits, spay/neuter etc... the list goes on. The adoption fee, is to try to get enough money to keep doing these generous deeds. They rely solely upon donations and adoption fees. I'm not sure about a pound dog though. You may check. Of course you can always save a starving one from the streets as I did with my second dog. If money is super tight, you may need to be sure you can afford vet bills, and food, as that is my biggest household expense currently. Hope you find a great one and give it a wonderful home. So many animal badly need good loving homes.