Technically, she didn't pull it out of the air. The atmosphere is made of water and oxygen, she just removed the water.

I think an easy fix might be to just say you can't effect people directly, the main reason Jimmy's semblance doesn't work on people is because their aura nullifies his. 

Our Semblances are our aura manifested and when we move things with it, we're putting a little bit of ourselves in it. Jimmy's aura can't go into something protected by another aura so his Semblance doesn't work on people. Like wise, it means he can't use it on a weapon if aura is running through it.

[@greywolf375] Your Semblance could just work like mine in that principal. Meaning that while you [b]could[/b] potentially manipulate a person, said person can shrug it off with will power.

That, or we could say you have to be able to see whatever you're manipulating so anything out of sight is out of range.

Just an idea....