Somewhat, she is noted in the games to give off the impression of just being a "normal" girl, but we don't often see that when interacting with her. One can only assume she is trying to be professional when interacting with the player because they are meeting her as island challengers (and even then the facade cracks some, like when after losing to the player in the Grand Challenge she tries some sage wisdom, then gives that silly smile and remarks "you guys are great!"). Her concept art also indicates that she is quite silly at heart, as does that ending image in the game of her enjoying mallow's cooking.Yup, they did...something to her: they made her basically a version of Whitney with a slightly bigger brain.
So much for how different she is in the games, exuding this air of professionalism.
Basically she is still accurate to her in-game personality, we just get to see more of the "real" her here.