Thanks so much for posting this. Your sketches help remind me of how our drawings are based on simple shapes before the detail is added. I always freak out when trying to draw humans but this example has helped me realize what I kept forgetting to do in the first place.
Those are quite good sketches of her. Lilo seems quite hard to draw, but Stitch is a bit easier IMO. Usually, his head is in a shape of an upside-down cup with a round koala nose, chihuahua ears, big black eyes, and such. I did try drawing him once with his mouth closes, drawings him with his mouth open was difficult for me.