Rescue Cat Background?

Is there a way to get the background of my rescue cat (Snuggles) other than the cattery at the RSPCA where she choose me? She can swipe (albeit claws retracted) if petted around the pack of her neck and hated it when I put a collar on her so she could display she had been microchipped, although seemed to be fine wearing it! I was wondering if someone had been scruffing her in her previous family. Any ideas or feedback greatly appreciated