Nancy Sinatra Talks Frank Sinatra, Mia Farrow and Ronan Farrow Paternity Rumor

The legendary crooner's oldest daughter speaks out about Mia Farrow

Nancy Sinatra is dismissing the notion that Mia Farrow's now 27-year-old son Ronan is the biological son of her late father, legendary singer Frank Sinatra.

In a new interview with CBS Sunday Morning, Frank's 74-year-old daughter addresses Mia's headline-making response to Vanity Fair's 2013 question asking if her son Ronan could be Sinatra's biological child. "Possibly," Mia replied, leading many to speculate about her vague answer. Ronan is the legal child of director Woody Allen, but no DNA test has ever actually been done. 

"Oh, nonsense," Nancy Jr. says about the rumor. "He would just laugh it off. We didn't laugh it off because it was affecting my kids, you know. They were being questioned about it and we all knew it was nonsense."

"I was cranky with her for saying that ["Possibly"] because she knew better, you know, she really did," she admits. "But she was making a joke! And it was taken very seriously, and was just silly, stupid."

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Mia was the legendary crooner's third wife, and was married to him from 1966-1968. According to Nancy Jr. -- who's the eldest child of Sinatra and his first wife, Nancy Barbado --  her father knew it wasn't going to "last very long" between him and Mia.

"Daddy said, 'I'm not sure it's gonna last very long. A couple of years, maybe, but I feel like we have to do this,'" Nancy Jr. claims in the new interview. "And I think, the truth be told, I think he didn't want her to be suffering because of him and she was being -- her name was being bandied about in the press and there were paparazzi everywhere. ... Well, I'm not saying that's the only reason but I think that was part of it. I think it was very important to him that she be presented as a lady and not be thought of as something other than just that."

Still, she says her and her siblings -- Tina Sinatra, 66, and Frank Sinatra Jr., 71 -- weren't against the relationship.

"We loved Mia," Nancy Jr. says about the Rosemary's Baby actress, who's actually four years younger than her. "Mia was like a sister. We had a good time. Tina, Mia and I did."

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Last October, Taylor Swift made headlines when she recreated Mia's famous 1974 People magazine cover. Watch below: