I felt like I wasfloating, like maybe I could fly. I wanted to be a HumanCannonball while I was still little enough to be thrownthrough the air
Simile - feeling like you could fly to represent the feeling of being weightless with relief after everything is resolved. Human cannonball represents that she only has a little bit of childhood left through the literally concept of weight, and outgrowing it.
Sonya embraces childhood - may as well enjoy it whilst you still can!