K.,
First, most kids only have one good meal of the day.
Secondly DO NOT MAKE IT A BATTLE!!! Offer the food and if she doesn't eat - NO PROBLEM!!! Offer snacks inbetween meals - very important. Try high calorie snacks or meals. Whole milk, butter, cooking in olive oil, drinkable yogurt or the baby yogurts, cheese, egg yolks, avocado (can be mushed with banana or pear) and even ice cream.
Try letting her feed herself. I do this by giving my daughter a 'baby proof' bowl with a spoonful or 2 of whatever the meal is and letting her try and feed herself while I'm spooning the food into her out of another bowl. She is distracted by trying to feed herself and it lets me get a bit of the food into her. If it is yogurt I am feeding her I give her an old yogurt container with some yogurt in it. Sometimes even with this she wants the bowl I have. I generally try to put it on her tray and let her eat out of it while I hold it down. Also if they want to 'get into it' with their hands -it a good thing. Give her 1/2 an avocado and a spoon, show her how to get the fruit out and see if she used the spoon or not. Allow her to mangle the avocado with her hands. The more they play with the food the better. Allow her to get messy and DON'T clean her up til the end of the meal. This is fun for them and the exploration is good.
The feeding specialist we have seen says to offer 3 to 4 different items at a main meal and 1 to 2 at a snack. Don't keep offering different foods until the child descides OK, I will eat that. If they don't eat - no problem, end the meal after 1/2 hour to 45 minutes if it last that long and then in a little while (depends on the child) offer them a snack (something different then the meal - hopefully something you know they will eat). I try to have at least 1 most of the time 2 of the 4 items at her meals, things that I know she will eat - whatever that is. The other items can be new foods or new textures. Remember it takes some kids 10, 12 or even more times seeing and trying a new food or texture before they accept it.
Also some kids are social eaters. They like it when they are eating with others, ie the parents or their friends. I know my daughter always eats better when her friends are eating with her. I try and meet up with friends in the morning and have lunch with them so she can have that social atmosphere. Sometimes just going to a lunch place by ourselves works too.
All in all don't make this an issue. It will resolve itself as long as you let her be in control of what she eats and how she eats it. But if you push it can become something that is worse late on.
Good luck,
L. M