Picky Poor eater

Swetha has strong likes and dislikes for food. I used tell myself , my food is good , if swetha eats it. Idli should be very soft. Dosai should be golden brown. She likes pasta very much. The only thing which she never say No is Icecream. But she does not like milk at all. She has developed a great aversion. Donot know why. Milk in any form , will take a long time for her to finish. If I am home , I used to tell her stories and feed her. Bharat with morning office meetings cannot do that. So I am giving her eggs now-a-days to fulfill the protein and calcium needs. She does not eat spicy food.She's very lean .When I see other kids of her age , she's just half in their weight. Sometimes I used to worry about that a lot. Thinking everyday about how to handle this problem. Hope I will get some help