As a mum of a child who had extreme issues with food at 2 (who is 6 now and much better although not a perfect eater by a long shot) I really wouldn;t go down this route!. When my DS was 2 he would typically eat toast, a toasted bagel and a chocolate mousse with a bit of fruit throughout the day! A year going through feeding clinic, as well as removal of tonsils and adennoids and he started to get thorugh this and at 6 is a normal sized, smart boy who eats pretty well, and you wouldn;t know he ever had problems.
Please dont stress about how much she eats in a day - dont compare her to your friends children, dont force her to finish everything up.
The best you can do is offer a wide range of foods, and snacks throughout the day, keep mealtimes lighthearted and encourage her to try foods. If she is happy, relaxed and healthy he will likely grow up being a good eater. The more stress you bring the more you will get.
Somedays she will eat like a sparrow, others she will eat like a horse, please dont focus on each individual day
If she is active, full of energy and is growing then dont worry, just keep offering a balanced nutritional diet and she will regulate her own portions based on her own hunger - this is a real lesson for children to learn and one which children who are forced to finish their plate don;t learn.
Also, many of our parents and grandparents came from post war era where food was scarce hence the finish your plate mentality came from, quite understandably. FOrtunately we are not in that situation now, but the trend has remained and now our portion sizes are much bigger than they used to be.
Sorry, didn't mean for it to sound like a lecture, but having struggled for years it saddens me when people start stressing so much about food around their children. Use your DD as a cue - if she is hungry she can ask for more or have a snack, but its really not uncommon for children of this age to live practically on fresh air.