Hi....I'm not sure about what pattern you should do....but I was in our local quilt shop in the UK this week and they were very excited about the 3D space fabric that they had coming in from Hoffman.....not sure if you have it already in the US as we are often way behind...but it would be great for an 11 year old...apparently it looks normal until you put on the 3D glasses and then the space ships and planets really pop out at you....don't think it's that expensive and would be such fun and unique
I have googled the following site that has a bit more info...also do a fish and a forest pattern I think.....Good luck
http://www.amidonquiltworks.com/fabric3d.php
PS...sorry have just realised you are in Australia but hopefully you can find a store to ship some otherwise I will happily send you some when our store gets some in...if you want some let me know.