I didn't have this doll but several of my friends did. Chrissy had short hair but it would grow if you turned the knob on her back. To make her hair short again you would press a button on her belly. I wished I had a Chrissy doll!
I'm not sure what we called this toy, but the box says it is a "Miracle Wheel". I know we didn't call it that. With a flick of the wrist you could make the wheel travel along the wire frame and defy gravity. It was my brother's.