Of course she'd never actually want to inflate herself.
Well, maybe a little bit, but never if there was any risk of floating away.
Okay, maybe floating would be fun, but only if was safe and controlled.
But she wouldn't want to get too big. Although big might be fun if she wasn't in danger of bursting. She might be okay with being a human parade float, as long as she could still stay curvy. A nice huge pair of balloon boobs, with a pneumatic caboose to go with it. And maybe a little extra around the middle.
Or maybe a lot.