They have been saying this every time before she fights. Then she destroys her opponent in the first round. Has she ever gone to a second round? Don't think so. In fact, most of her wins have been in less than a minute. She also fights in her weight class, which is the same one that Tate is in, so the size argument doesn't hold true.
She is also working her ass off to get better at all aspects of MMA, just like every other successful MMA fighter does. They basically come into the sport with a specialty that they excel at and learn the rest to stay competitive.
BTW, TUF is just like any other reality show and they want and encourage drama. That's why I stopped watching it a couple of seasons ago. My judgment of her will not be effected by what she says or does on the show. Well, maybe it will show that she's a good actor.
you should also understand that every time a fighter cuts a lot to make weight it also weakens them. It's a sign of their physical ability to cut and still fight well. If Carmouche was as physically capable as Ronda, she could also walk around at 150lb.
Time will tell all. 
