Do you have a picture?

Is the bloating right up to the vent area?
If it ends at the vent, then I suggest giving a warm soak until something comes out. Has she pooped or urated for you since this bloating has occurred?

Other than that, the only other thing I know of as of yet that can cause bloating is overheating. So check the temps.

Let us know, and if all else fails, take her to the vet.