Is it possible that Faith believes that she is pregnant?

Sure sounds like a pseudo-pregnancy to me! If she in unspayed and was in heat recently (about 60 or so days ago) this could be the problem. If it is a false pregnancy, it should end in about 3 weeks. If it's a real problem, the vet can give her a shot to help. If she isn't spayed and she is a family pet, then you should have her spayed. Unspayed dogs can continue to go through false pregnancies, usually with greater intensity as they get older, and are prone to health difficulties as they get older.
However, if she is already spayed, that is not the problem. Then you should definitely take her to the vet for an evaluation.
Hope this helps!
Didi