Try meal worms, bread, watermelon, lettuce, millet seed, or anything else that she will eat. This will affect her feces and sort of take that away as a diagnostic tool, but she'll need the energy.
The losing balance can mean something. Is she cognitive? Looking around and such? Is she able to walk normally, without staggering or falling over?
The two common things that immediately come to mind are nerve damage and a head wound. Most anything else that affects her balance is much less likely (and worse). If she hit her head hard enough to cause swelling that could cause these symptoms. Not drinking, which they sometimes do for no good reason it seem like, can cause permanent nerve damage that affects balance. She'd heal from the first, the second she'd get worse and need to be put down. I recently had to put down a roo at friends house who had no visible damage to his head but, walked backwards and looked upward, everywhere he went. Head wounds, even light ones can cause strange behavior.
Other things that can affect balance are Mareks, Encephalitis, and botulism from bad feed. I wouldn't worry about these yet, but since your her vet you can keep an eye out for other symptoms of these diseases just to be safe.
