I saw one of her on the beach changing into a bikini....not sure it really was her....it was a very rude shot.
I know the picture you're referring to. No, it wasn't Jenna Bush. (or Jenna's Bush, for that matter)
She was waving to the press inside a car with her father, she continued waving, smiling and then stuck her tongue out for fun. After she did that she laughed and waved some more.
Yeah, there was something similar with the video clip of then-Governor Bush giving the finger. Viewed in context, it was clearly a joke... someone off-camera asked him to fix his hair, he rolled his eyes, ran his fingers briefly through his hair, flipped the bird to the camera, then laughed. An obviously lighthearted moment, but various Democratic organizations clipped out the context and just use footage of him making an obscene gesture to imply he was being rude.