Where are you located?
Is she taking any classes?
In my opinion and experience, if you are serious about getting the girls into film, you'll want to at least consider relocating. New York, Atlanta, LA are the absolute hotspots for anyone trying to get into film, but LA is tops. Not to many production companies will be willing to fly in a child for an audition when they have hundreds on hand to choose from. It's always good to check in with local theatres and see what shows they are putting on, and if they have any parts for children. I'm going to give you this link to look over, she gives the same advice I would give you. After you look it over, let me know if you have any additional questions.