I picked up some dry cat food, jarred baby food (oceansedge's suggestion) and a couple more varieties of catfood. I set out a couple of tablespoons of dry cat food at around noon, and Ash promptly ate it. Wow!
And that's the end of the good news, because she hasn't eaten anything else since. Tried tempting her with cat milk and baby food, no luck. Left out some dry cat food, but she hasn't touched it.
The vet wanted to see her again on Monday anyway, so Lut'll bring her back then and we'll see if he's got any new ideas.