Wow gloomgirl - that looks fab!!
Mine was less complex - I just wrapped ribbon round the Barbie's body, and then layered ready to roll icing over the cake part, and stuck on flowers. Get the ready coloured icing as if you want to do a vibrant colour with food colouring, you have to add so much that it tastes disgusting!!
After nearly 7 years, I have now come to the conclusion that (a) icing hides a multitude of sins, and (b) kids think that whatever you produce is fantastic!