Ivana Trump, who is attending the Paris haute couture shows this week with her partner, Rossano Rubicondi, said she recently advised Trump and O'Donnell to make peace in her advice column for the National Enquirer and Globe tabloids.
"I was very diplomatic and at the end of the day, I said, 'You know, guys, just take the high road, it is so ridiculous,"' she told AP Television News on Wednesday.
She said the feud is just for show.
"Donald and Rosie, they're getting fantastic ratings, they're getting publicity, they're really using it as a marketing tool, not because they are enemies, and I understand that only too well."
The fight between Trump, 60, and the 44-year-old O'Donnell, moderator of ABC's "The View," broke out last month after Trump announced that Miss USA Tara Conner would keep her title, which had been in jeopardy because of underage drinking. He owns the pageant.
O'Donnell said the twice-divorced real-estate mogul had no right to be "the moral compass for 20-year-olds in America." Trump fired back in various interviews, calling O'Donnell a "loser" and a "degenerate."
Trump, host of NBC's "The Apprentice," said earlier this month that he was finished with the quarrel -- before fanning its fires a little further.
"Not everybody has to be politically correct," he said. "I think that's why this so-called feud took on a life of its own, because it wasn't politically correct. In a way it's wonderful that she doesn't like me and I don't like her. There's nothing wrong with that."