I wouldn't start worrying just yet, especially since she's never been a big eater. If you start seeing weight loss or consistent night wakings that are clearly hunger, then something else might be going on. I agree that finger foods might be the way to go for the time being...the toast diet is pretty common, especially when teething. If she wants toast and rice cakes, why not let her have them and find ways to add variety? You can spread veggie or fruit puree on those or use egg yolk to make eggy bread/french toast. You can also break up crackers into smaller pieces and spread stuff on those too. When Tyler went on the toast diet, we found that he also would eat sandwiches cut into bits and squashed down slightly, and you can spread all kinds of things in there. And you can often get away with coating fruits and veggies in dry infant cereal or crushed cheerios to make them more "bready."
The only thing you have to keep an eye out for on the bread diet is constipation, which can usually be fixed with using prune puree as a spread. Keep offering other foods because you never know when she might try something new!
