Hi there,
I think if she is a picky eater you can choose snacks like granola bars, sweet snacks and whole grains that supply her with good nutrients. Keep her away from soda, chips and other kinds of junk food, which is not healthy for her. A healthy nutritional diet is the key component for body growth and development.
It mainly revolves around 3 factors i.e. look better, feel better and live longer. If she does not like home made food, try to choose between readymade food products. There are several companies such as Sheffafoods.com, healthysnackstore.com and others that sell packaged snack foods that are natural and sure to be delightful for your daughter as well.