Overall she ate almost a whole can of cat food, and a smallish saucer of cat milk yesterday, which isn't a patch on what she ate previously.
I heated up some more smelly fish cat food (more of Talisker's old supply of Encore, most of the kitten food isn't that strong smelling, or fish flavoured), and also some milk.
She's had a little of both, although barely enough of the milk to notice. Clearly she either hasn't got an appetite, or it doesn't smell right. Previously she was glugging the milk down, almost an entire bottle in one day!
From an energy point of view, she still has plenty, she'll bounce around like a mad thing if you play with her, and is doing some stuff even when I'm not in the room. She's also using her litter tray, so there's clearly stuff going through her, but not as much as before.
I think she should be OK for a while, as long as she's not torpid and lethargic, I think she's OK, and I'll be seeing the vet tomorrow morning, so I'll ask him when I should start worrying, and need to ring them up.