I finished the chemo hat while watching Wimbledon. It's washed and blocking now. The picture on the left is the top, and the picture on the right is the under side. You can't see the shape right now, but think of it as one of those collapsible top hats in its collapsed state.
The yarn is 100% mercerized cotton, washable. It's very soft, so it shouldn't feel scratchy on a bald head.
I hope she likes it. I'll take it in to the library with me on Saturday.