My three and a half year old son went through (and still goes through) phases like that, and my mother tells me I did too. When I was little, my mother asked her doctor about it, and he said that as long as I was healthy and still gaining a little weight that I would be fine. You'll notice as she gets older that she all of the sudden will be eating ALOT, and you'll know that's your cue that she's going to need new clothes! You may want to start keeping track of how much she nurses, and maybe change your feeding schedule a little...at that age, my son would fill up on formula or milk and not be hungry. (we still have to keep an eye on how much milk he drinks and when he drinks it)
Another thing you might want to consider is texture. My son went from a baby who would eat any baby food you gave him, to a kid who only likes chicken fingers, turkey dogs, corn, apples and grains of just about any kind...I've been told this is pretty normal, and as long as he gets his vitamins every day and I watch his weight, he's fine. I swear he lived on Cinnamon Raisin Oatmeal baby food for two months!
Also, once they get to be around two, what food they eat is one of the few things they have control over, so don't sweat it as long as she's healthy, and just keep introducing new foods when you can. What I do is make a regular dinner, and just make sure he gets one thing I know he'll eat alot of. We actually kept giving him stage 3 baby food until he was almost three, just because there's so much adult food he doesn't like.