Does she seem to be adjusting otherwise? If she isn't, you might want to look into shutting her into one room, like your bedroom, with her food, water, and litter box for a a few days/weeks until she feels safe in that room. Exploring a whole house can be scary and she might be super stressed.
Do you know what the shelter was feeding her? Maybe buy that type of food. Try feeding her some real meat or an egg or even tuna if you don't think she's been eating, as it's very important they eat, there can be fatal consequences quite quickly in cats otherwise, as they can suffer from hepatic lipidosis.
Last edited by Carmel; 01-20-2013 at 08:33 PM.