How was yesterday? Was she any better? Has she got a temperature? You could try her with some ibruprofen about half an hour before solids to see if that help. Is she showing any other signs of illness, often things like ear infections cause them to eat and feed less and can be hard to pick up on.
If you think it might be teething, I'd give her the ibruprofen and try her with a teething gel like Dentinox. Frozen bananas and chuncks of cool cucumber work well too and I always gave mine a clean wet flannel to chew on.
Are you bfing Pasta? If so I dould seriously not worry about how much she is eating at this age. Mine had phases when they would have more solids and at other times more milk. Try to look at what she has eaten over a week rather than a day .
Mine goes through phases which I referred to as a strike too! Could be a slight cold, sore throat, feeling sick, teething or anything else really. It usually gets better after a week or so. Maybe give her high calorie food like cheese for a while.