I agree with snowolf, it's mostly about upper body rotation at that age, any analogy/game you can do that gets her to point her shoulder/front arm will work, just make sure she is comfortable sliding on her toe edge first before you try and make any turns. Most 7 year olds I have taught hate being in their toes because they can't see down the hill.
I will add that the right equipment makes a massive difference at that age. The stuff burton is coming out with right now is amazing. Reverse Camber with a beveled base does wonders for the little ones. Going a little bit shorter can help also.