Beautiful quilt - I love your original design! I don't usually like pinwheels but they are very cool in this quilt.
I found it quite interesting that I posted my original Dr. Seuss quilt the same day you posted yours! You can see it here:
http://www.quiltingboard.com/t-106416-1.htm
Your sister will love this! Dr. Seuss was a great man who did so much for kids and reading. But there was a lot more to him than that.