So the vet thinks her liver is failing and he/she isn't keeping her for treatment?
I have no idea if it is a shunt or what but the symptoms kind of say poisoning to me.
Is she on Denosyl, fluids, etc.?
Please take her to an internist immediately (MSU and Oakland Referral take emergencies) and consider getting a new regular vet because it doesn't sound like this one is much help.
