Facebook says Florence Detlor, 101, is its oldest registered user

(CNN) -- She may be nearly four times as old as its founder, but Florence Detlor likes Facebook. At 101 years old, she's been named by the social network as the oldest of their 900 million registered users.

And she also happens to live near Facebook's headquarters in Menlo Park, California, a fact that helped her get a personal tour and chance to meet some of the site's leaders.

On her own page, Facebook Chief Operating Officer Sheryl Sandberg posted a photo Monday of herself, Detlor and CEO Mark Zuckerberg (who is 28, the same age Detlor was in 1939).

"Honored to meet Florence Detlor, who at 101 years old is the oldest registered Facebook user," Sandberg wrote. "Thank you for visiting us Florence!"

Detlor says on her profile page that she's a 1932 graduate of Occidental College. She joined the site almost exactly three years ago (August 19, 2009). As of Tuesday morning, Detlor had 652 Facebook friends.

"I like to think of new friends," she posted Monday, suggesting that some on that list may have appeared thanks to her 15 minutes of social-media fame.

She's a regular, but not overly prolific, poster on the site. But in three years, she's "liked" only two things: the Sony Dash, a pre-iPad tablet of sorts, and Dogwork.com, a site that specializes in animal videos.

Detlor's status as Facebook's oldest active user has already inspired some light-hearted competition.

"Ok -- so now I'm feeling competitive and ready to get my grandma on Facebook. She's 103. ;-)" wrote a commenter on Sandberg's page.

Detlor may be on the extreme end, but she's part of a trend that's been evident for the past few years.

The percentage of Internet users 50 and up who said they use social-networking sites spiked from 22% in 2009 to 42% the next year, according to a survey by the Pew Research Center.

Respondents 65 and older reported a 100% increase, while those between 50 and 64 jumped 88%. By comparison, the number of users from 18-29 who said they use networking sites rose a much more meager 13%.