Updated 10:20 p.m.: TMZ and CBS are reporting that Ephron has passed away. 

Previous: A spokesperson for Nora Ephron's publisher Knopf denied an earlier report the novelist and screenwriter had died, but confirmed that she is ill. "It's pretty critical. She's not doing well, but she's certainly alive," said Elizabeth Lindsay. "The report she has passed away is not correct." ABC News reported that Bryan Lourd, co-chairman of Ephron's agency, told the network she is suffering from leukemia. Their subsequently published story quoted friends who said she is gravely ill.

Born in 1941, Ephron graduated from Wellesley College and worked as an intern in John F. Kennedy's White House and in Newsweek's mailroom before eventually landing at the New York Post as a general assignment reporter 1963 — breaking society stories while writing essays for the likes of New YorkEsquire, and The New York Times Magazine well into the 1970s. 

It was in 1976, she married Carl Bernstein, and it was during that marriage that she got her first crack at screenwriting by rewriting William Goldman's script for All The President's Men, and though it was rejected, it got Ephron into screenwriting, "a horrible television movie" she told The Guardian's Emma Brockes in 2007.

Heartburn, which was widely regarded as a narrative of her breakup with Bernstein was published in 1983, and made into a movie starring Meryl Street and Jack Nicholson in 1986. She wrote the major hit When Harry Met Sally... (directed by Rob Reiner), which was released in 1989, and again struck romantic comedy gold when Sleepless in Seattle was released in 1993. Julie & Julia in 2009, was the last film she wrote and directed.

Her books include Wallflower at the Orgy and Crazy Salad. Her most recent book is I Remember Nothing: And Other Reflections.

In a colossal screw-up Tuesday afternoon, the website Wowowow.com appears to have prematurely published an obituary by gossip columnist Liz Smith stating that Ephron had died. The early publication of Smith's obituary spurred frenzied speculation on Twitter. Smith defended her story to The Hollywood Reporter, saying she had spoken to Ephron's son Jacob Bernstein, a writer at The New York Times. “I was told this morning that she was dying, but I can’t confirm it,” she said, adding that Bernstein told her a funeral was being planned. “It’s bad enough that she’s dying, but I don’t want to be the cause for everyone to grieve in advance." That, of course, is exactly what has happened. 

It's common for outlets to write obituaries in advance — and Smith's, which only mentioned Ephron's supposed death in the second-to-last paragraph, looks like such a case — but it's highly embarrassing when someone hits the publishing button while the subject is still alive. Bloomberg ran Steve Job's obituary in 2008, three years before his death last October. CNN's cache of prepared in advance web tributes briefly went live in 2009