I've read Spinel's article over a couple of times, and in the power section I noticed an ability called "Levitation." Given that Spinel is so bouncy and elastic, I wouldn't be surprised if she was able to inflate and have the air carry her upwards/slow her descent. Thoughts?
Possible, but it's not how lighter-than-air floating technically works. The air inside the object has to be lighter than the air outside, such that overall the mass of the object is less than the mass of air it displaces 🤓 She'd be able to float if she could either heat the air she was holding (making it expand, reducing the density and the mass per ㎥) or replace it with something lighter than air like hydrogen or helium.