Though I avoid walmart, they have good prices on Fuji film.
I was probably younger than 7 when I had my first camera... the Brownie Holiday that was my mother's when she was a child. I have a lot of blurred images from not holding the camera still when pressing the button.
No doubt you'll start your daughter with a more manageable camera, but might I suggest a 400-speed film? It will be less likely to blur her pictures if she can use faster shutter speeds. As a matter of fact, my best friend took a picture of myself standing next to Mr. Potato head at the Hasbro Headquarters in RI with my Sears KS-2 on a very sunny day, and she blurred the picture by moving the camera while pressing the button - and she was in her late twenties.