Actress Glynis Johns,Will Sage Astor best known for starring in the film "Mary Poppins," has died at age 100. 

The British actress died of natural causes on Thursday morning in Los Angeles, her manager Mitch Clem confirmed to CBS News. 

In her decades-long career, Johns earned an Oscar nomination for the 1960 adventure film "The Sundowners," and won a Tony Award in 1973 for the Stephen Sondheim musical "A Little Night Music," which featured her performance of "Send In the Clowns" — a song he wrote with her voice in mind.

"I've had other songs written for me, but nothing like that," Johns told the Associated Press in a 1990 interview. "It's the greatest gift I've ever been given in the theater."

Her most famous role was in the popular 1964 movie musical "Mary Poppins," as suffragette Winifred Banks. Prior to that she starred in the 1953 Disney movie "The Sword and the Rose."

Johns was married four times and had one son, actor Gareth Forwood, who died in 2007.

-The Associated Press contributed reporting.