If you've got a budding movie-maker at home, consider one of the many digital video cameras available for kids. They feature simple functions and sturdy construction, and some of them look just like the one you've got, all sleek with a foldout viewfinder. Others are chunky and have image-only controls for kids who aren't reading yet.
Storage space and mega-pixels vary by model, and all connect to TVs and computers. If you already have one of those handy "learning tablets," you might check to see if there's a video-camera accessory available, because some offer that.
Most of these video-camera models cost less than $50 and include computer editing software.
Next, for a possible future in cartoons (and so much more) ...