I heard on a satellite radio program about picky eaters that it can take 10 to 15 times of exposing kids to a certain food item to get them to eat it. So, don't give up. I have two kids who have both been picky eaters from time to time. Both during their toddler years. My one son now tries many things and has a varied diet. My other son has sensory integration disorder and texture issues with food really cause an issue for him. He also has trouble chewing and has gagged many times on meat so is super picky about protein. It's a pain. :>) I know. Things to also try---- we use a 'trying bowl'. My kids get a bowl of something new which is something to try. They get praised like they just ran a marathon for taking a bite. We let them get involved in choices. You can have A, B or C but you have to eat what you pick. You provide 3 healthy choices. Dipping . . . kids love to dip. My kids like ranch dressing, barbeque sauce, salsa and hummus. This masks a lot of foods they aren't sure about. Speaking of which, I've snuck in many a vegetable into things like a smoothie (if you cut spinach or kale up and put in blender--- they never know it is there, same with carrot juice). Vegies in pasta sauce. Etc. The two bite club is good-- make a big deal about dad is a member of the two bite club (he takes two bites), mom is the member of the two bite club (she takes two bites) --- don't you want to be a member and take your two bites? Kids don't actually need to eat a lot-- my doctor showed me that about the size of their palm is a meal for them.
Anyway, my second son is small and always has been. He is in the 30th percentile for weight. My other son is big and tall. They are opposite. But both are healthy. So, just keep trying to add things in.
Does she like fruit? Bean burritos? Home made macaroni and cheese?