She's a sixteen year old girl. . . that's how they act lo l. I don't believe she is necessarily stupid although she's not the most eloquent kid at that age. Maybe that's what people expect if you're playing with the adults. You know?
I think her 'golf maturity' is far above average for her age, while the rest may just be average. People develop in different speeds as well, and she may be nervous 'on the inside' which influences her to say things that she wouldn't if she were more comfortable. Not that she says things terribly stupid - just not that sharp. Being infront of a camera changes people, some more than others, and in different ways. I think it's very possible, as others have said, that she hasn't fully grown into her popularity.
Or maybe she's just a bimbo. A hot one. :p
And Chambo that was hilarious. "But I'm only 17!" Pure gold.