Eight weeks old... if she had never had greens before coming to you, then the grass and dandelions could be part of the problem. Kits that have access to greens from the very beginning develop the gut flora they need to digest them, but older kits giveng sudden exposure to greens may eat more than they can handle. But although that might cause poopy butt or diarrhea, this sounds like something more.
Unless you know a vet with lots of rabbit experience (perhaps the breeder can suggest one) then it may be worse than useless to take the rabbit to one. They tend to reach for the antibiotics, from what I have heard from others who have gone that route, and there are few antibiotics that rabbits tolerate well. Expensive too...
I'd give the rabbit grass hay and kitchen oatmeal and the plants I suggested if you can find them. That an water. If you are force feeding or syringing fluids you must be very careful that the rabbit does not aspirate the food/water.
-- Tue Apr 15, 2014 6:22 pm --
Oops! Just realized that the useful plant information was posted in a different thread, so I've copied and pasted it for you here.
If you can get any of the following plants, they are all safe for rabbit food and good medicine against diarrhea:
- raspberry, strawberry or blackberry leaves
- the lawn weeds plantain or shepherd's purse.
http://en.wikipedia.org/wiki/Plantago_major
http://en.wikipedia.org/wiki/Capsella_b ... a-pastoris
These plants work fresh or dried and it is a good idea to have some on hand for these situations.
IThese plants may or may not be growing yet where you are, but if you have green grass and dandelions then perhaps you can find them.