Penny Marshall Candid on Cancer Scare & 'L&S' Feud

At 68, Penny Marshall is still as fiery as ever.

The legendary comedienne and director recently sat down with ET, letting loose on rumors about her ill health and the alleged feud between her Laverne & Shirley co-star Cindy Williams.

Related: Penny Marshall's Hospital Stay Explained

"[I'm] clean as a whistle," asserts Marshall, who credits sensationalist tabloids (or "rags") -- and their recent claims that she nearly died following a cancer/brain tumor scare -- with inspiring her to pen her new memoir My Mother is Nuts.

"The rags write about it and they're wrong…They have me dying every three months," she said. "It's bulls—t. I can't get work so I wrote a book instead."

Video: Maria Shriver Confronts Paparazzi

The actress, who has been in the business since her early twenties, also credits the news media for the downward spiral of young stars in Hollywood today.  

"It had always been, you know, if you had been lucky enough to be successful they were waiting for you to fail," Marshall says. "There are a lot of young actors who do great, and then there are some who like to party a little too much. Then it goes on and on in the news and … they keep repeating it over and over."

As for tabloid rumors that have persisted since her Laverne & Shirley days, she sets the record straight on the alleged feud with her co-star Cindy Williams. 

Related: Justin Bieber's 911 Call During Paparazzi Chase

"We get along great... I talked to her yesterday," Marshall revealed, adding her admitted distaste for Williams' husband (whom she felt was too controlling) likely fueled the rumors.

Watch the video for more of Marshall's candid interview.

My Mother is Nuts hits shelves September 18.