She really does need to get her gut working again to give her a chance, if she's not in pain she may have more of an appetite

If she smells I would ask the vet to check for a urinary tract infection (if it smells of urine or stale urine), for this she would probably need an antibiotic & painkiller.
Stones or bladder sludge could also a possibility if its urinary related, if her urine is gritty to touch& more white in appearance it can be because there's to much calcium in her body.
If it smells bad in her genital region but not of urine, I would get the vet to check for womb problems, infection, pyometria?
In which case antibiotics or possibly a spay may be needed
I wouldn't be surprised if they suggested a gut stimulant too (or two, one for both parts of the gut) to help get her eating again.
Whichever conclusion the vet comes to.
Is she still pooping OK?
If she's hopping she must be in pain so she really needs painkillers of some description & fast.
Xx