I doubt that it would be easy. You will have to do a bit of modifications. Besides the fact that it won't have any braze-ons (easily fixed with p-clamps), racks are not made for such small frames. Getting a rack to fit a small adult's frame is difficult, this thing would be a pain. I'm not saying it can't be done, but it won't be easy. You'll need to make some kind of bracket to attach the top of the rack to the frame.

Any reason you don't want an Extrawheel? I assume because of the cost. It is much more expensive than $84.