Noticed she crawled much better on the bed then on the floor (don't worry, I make sure she doesn't go off the edge) so I took some foam I had in the craft closet, wrapped one of our many baby blankets around it and pinned it in place, and put that down in her play area. Now she crawls well there too. Maybe something about the harder floor or the scratchy carpet was putting her off? In any case, her crawling is developing well.
Also she now will pick up something and hand it to you. Then you can hand it back to her. That makes for a fun game and teaches her some good interpersonal stuff.