Taking the artists background into consideration and also the other work that she has done, I really don't think this is just meant to be an innocent photo..( the bolding is mine)
Goldin, 54, is well known for her shots of young, semi-clothed girls.

... and she has been criticised for glamourising drug use Thanksgiving is described by the Baltic as an installation of photographs which documents Goldin's life from 1973 to 1999 - "a micro-retrospective of her career."
In 2001, one of her photos featuring a very young naked girl looking up between the open legs of a semi-clothed older child had been criticised for making money from exploiting children. It was published in a book alongside similar works to accompany an exhibition at the Saatchi Gallery in north London.
Goldin was born in Washington DC, ran away from home and was fostered by several families during her childhood. She moved to New York after graduating from art school where she took became known for pictures of alcoholics, drug addicts and Aids sufferers.
She was admitted to rehab in the 1990s and much of her work since has reflected her own experiences.
Sir Elton John has long been an admirer of her work and is also a close friend.
Seized 'art porn' owned by Sir Elton John - Telegraph
Okay, she's photographed young girls before and has been critized for it so it seems that this isn't a one off innocent pic of young girls.
And apparently according to this article
much of her work has reflected her own experiences.
So maybe she was photographed naked in these kinds of poses as a young girl by some one.
However, why she should want to do the same to another child is a bit beyond me.
It all seems a bit fucked IMO.
As for Elton, I really don't think that he's part of this story.
He is a personal friend of the artist and more than likely just bought a batch of her work without even looking at it.
He apparently often gets other people to buy his art and he stores it away as an investment. He doesn't show a lot of his art that he's bought.