All the progression in the game is equipment-based! So stats-wise she's just locked to whatever items are available at that point in the game. However, her battle abilities are well-rounded by design, as opposed to being specialized—she's the only character who doesn't have any unique abilities, but she's also the only character who can both build the stagger bar _and_ exploit it.
Ah, okay. Option one, more or less; that makes sense. i don't know what the "stagger bar is" beyond reasonably inferences, but that sounds pretty neat.
I was just thinking in terms of "she's deliberately pulling her punches to stay average, so maybe that means she doesn't gain power like the other characters who presumably can't just decide to hit twice as hard if they feel like it." Speculation getting ahead of facts.