Two items:
1) She hasn’t been with you long, so the comfort level isn’t there. She’s a prey animal, so staying in a single spot that seems safe is the best survival tactic.
2) Rabbits are silent sufferers, meaning they do not verbalize when they feel pain or discomfort unless it’s excruciating (then they scream which is terrifying). A rabbit who’s reluctant to move and remains in a loaf position could be in pain.
Can you provide some more information:
1) Do you know if she’s spayed? I know she’s 6yo, so if she isn’t, there’s a high chance of cancer for her.
2) Aside from veggie presentation and pellet presentation, do you see her eating hay at all?
3) How much non-hay foods do you give her? This includes treats, veggies, and pellets.
4) Do you notice or hear any sounds from her? Sounds may be a crunch from the teeth, gurgle from the stomach, breathing noises, etc.
The answers provided in this discussion are for general guideline purposes only. The information is not intended to diagnose or treat your pet. Seek the advice of your veterinarian or a qualified behaviorist.