The pretty kitty threw up huge on Saturday and hardly touched the food
in her bowl.  She did finish it Sunday (the same food that was poured
Saturday morning).

Monday, she seemed a bit slow in finishing her food - she hardly touched
(if at all) until after 6 and there was a little bit left this morning.

The same thing today - there's maybe 1/10th of it left when normally it
would be finished by now.

She seems a little sluggish, although if it weren't for the food
situation and the vomit on Saturday, I probably wouldn't even notice
that since it's not that unusual and I would figure she's just being a
cat.

Weirdly enough, I told her "If you don't eat your food, I'm taking you
to the vet tomorrow" and she started eating a little.  I don't really
think she understood me or the "threat" to take her to the vet, but it
was an interesting coincidence.

It may be nothing, but it seems she may not be feeling up to par, so
I'll let the vet check her out, but does anyone have any arm-chair
possible diagnoses?

She's an indoor cat, so she didn't eat a mouse or a bird that was past
its expiration date.