Can you confine her to one room with a litter tray for now? Is this the one that came from a farm? I'm guessing she'll need treating like a baby in regards to teaching her where to pee!
A tip for cleaning it up, use a biological washing powder and a 10% solution of surgical spirit mixed together in water, it gets rid of the smell completely so stops them thinking that everywhere is a toilet because it smells! It worked with Toby dog when he came home from the vets, I assume it will work with cats too.
I echo what 3B has said, also if this is the cat from the farm and they are house trained it may be possible she is a little stressed as she's moved house.
Better safe than sorry, if it is a stress thing you can get a spray/diffuser called feliway (have a google) I've used it with great success and we use it at the vets to chill out cats