ProudPiggyOwner, where are you giving her floor time? What sort of flooring does the area have? Are you having play time indoors or outdoors? Some things to take into consideration:
1.
Cavies do not respond well to slick surfaces. Linoleum, hardwood, tile, etc. are too slick for the
cavy to properly grip the surface and run around. Instead they sit there bewildered, uncertain of their footing. If you don't wish to have floor time on a carpeted surface, try laying an old comforter or some large towels on the floor to allow her more grip.
2. If you're playing with her outdoors, are there a lot of predatory animals or birds in the area? Even though the
cavies we own are domesticated, they still have all of their prey animal instincts. I keep Abby in our family room in our finished basement. During the day I open the screen door to the backyard to let the sunlight in. If she's out and about and a hawk screeches or a dog barks, she high-tails it back to her Pigloo.
3. Since you are still looking to adopt her a buddy, she may feel shy and overwhelmed.
Cavies love playing with one another and oftentimes will feed off of one another's energy and behavior. When I had my two boars, one was very shy. The other was a total ham. I'd put them on the living room floor and my shy guy hid under a chair. Until his cage buddy started running circles around the room. Little shy guy would quickly follow suit.