I'm in no way suggesting she looks bad, but these days she'd have to take off more than just her clothes to make her fighting weight.
I don't know if she has a fight coming up so I'm sure she hasn't been doing any hardcore training, she's never been what you'd call a petite woman.
This film is a pretty blatant, boring, formulaic attempt at selling us on a new sexy action star. Not that there's anything wrong with that, but it feels so forced it's almost awkward. If Carano is even a halfway decent actor (something I don't think she'll be capable of doing), she definitely has a career waiting for her. Seems like they're just trying to play it safe with her first role. Get a really cliche but serviceable script, sign up decent director, get a supporting cast with name recognition (but in reality has very little screen time), and insert your new-on-the-scene sex-symbol protagonist and hope to god she doesn't completely blow it.