The pattern I used is here: http://craftyboy.blogspot.com/2008/03/guest-postpattern.html
and here's my notes of what I did- I made a few changes.
Incidentally, I was correct, the bobble is not kid proof. I made a bunch of these to sell and a friend of mine bought one for his two year old, which I just KNEW was a bad idea. she had the bobble off in a couple of months. I figured as much. When he asked if I could fix it, I replaced the wire stem with a more kid-friendly braid. Sure, it didn't stand up any more, but the two year old didn't care.