OK, here's one that I've tried to find using the multiple site google search KindeyCracker did in post 18.
I don't recall the author but the story was as follows.
Written from the Husband's POV.
The couple lived in England.
The wife's sister got sick (cancer?) and the treatments were very expensive. She agreed to do a porn film to get the money and she and her husband flew to the Caribbean(?) to film the movie.
It had multiple sex scenes of her being filmed and she slept with the director/producer every night.
At the end of the filming, the husband found out that had won the lottery. He had been in a group of people at work who regularly bought tickets, and they had hit while he was away.
The sister ends up at a hospital in Arizona, and the wife goes to visit her regularly, The husband finds out she makes side trips to LA to visit with the people she made the porn film with, and maybe make more films.