I have that book too! I haven't tried any of the balls yet though. Yours turned out lovely. Did you find them easy to do?
I have the book and followed a workshop on knitting these balls but it did not help... I finished the one ball I started during the workshop but I never grasped how to start up a new one... so there is one knitted ball in my tree.... would love to make more because I did enjoy making that one and I still love the book.