I was told never to fight over food issues - because you will always loose and it's one of the few things that they can control. Also you need to look at the total food intake over a week to see if there is an issue.
So easy to say not to worry but I know that I do myself!

If you are worried after checking her food intake please see your GP. There are liquid vitamin and mineral drops that you can get so you know that she is getting all that she needs.