child averse to food and milk

my grand daughter who is  4 year old, do not show any interest or whatsoever to take food or milk right from the early days. Her parents try to feed her with great effort but the child doesnt cooperate. The attending doctor says that there is no problem with the child as long as she is active. the child is very active and hale , but very lean.Hardly she eats 4 to 5 spoons of food and a half glass of milk. Thats  all.Not more than that. Please advise us how to turn the mind of the child to eat properly the food  and drink milk regularly.

[margypops]

Let her feed herself ,she is old enough to eat alone not be fed unless she has a disability and has to be halped, let them put the food on the table and then eat their own food or leave her to eat hers , sometimes parents out of concern overdo the trying to get them to eat and it execerbates the problem ,give her healthy and tasty food and if she wont drink milk make it into a Milkshake , chocolate or strawberry,actually half a glass sems pretty good,