Where did you read this?
I read something quite similar in the Globe.
However, I have not heard/seen/read anything from a reputable source about it either way.
From what I've read, her parents were not on the set at the time of the so called "nude" shot, although her father had been there earlier. On the set at the time of the "nude" shot were her publicist and her grandmother, both of whom, according to Vanity Fair, approved the shot after it was taken and shown to them on the camera's digital screen.