The gun she is carrying is probably a plastic prop, but props in fiction like movies and TV often have new design elements that can catch on.
This has several interesting elements, and no I am not talking about the tiny hat.
Belt fed 12 gauge: I have seen some examples out there like this one. But not commercially.
Dog leg Pistol Grip: I have actually fired this kind of grip before. The are more comfy if shooting from the hip.
Chainsaw Grip: I have yet to fire a gun with a top mount chainsaw grip, but it's on my list.
--Put all these elements together in a real weapon and it would be a Lead Storm to put the old Street Sweeper to shame!