Flora will be great Just be ready for squeals and hug attacks. There's the Fairy Godmother too. The one at Disneyland is incredible, she takes time to play with the kids and leaves you feeling that you're the most important person in the world.
I'm not quite that shape and have somewhat given up on costumes. My sister wants me to go to Labyrinth thing with her, as I'll probably be minding the Jareth doll I'm going to wear all black and stick a Fiery (Chilly Down) or some other puppet on me.