Labine was born in Jacksonville, Florida on June 28, 1934. She attended the University of Kentucky where her major was journalism, but later she switched to playwriting major at Columbia University's School of Dramatic Arts (now Columbia University School of the Arts). After graduating, she joined the writing staff of Captain Kangaroo. After writing for the show for two years, she was fired in 1968. Her first foray into daytime was as a script writer for the CBS Daytime soap opera Where the Heart Is. After only a year at the show, she was promoted to the co-head writer in 1971. The show ended in 1973 when CBS chose to take the show off the air. Shortly after, Labine became head writer for another CBS soap, Love of Life. The ratings for the show rose, which brought them to the attention of rival network ABC.
In late 1974, ABC Daytime approached Labine about creating a new soap opera. The network wanted a soap opera similar to General Hospital. Ryan's Hope was created. While writing it, Ryan's Hope won six Daytime Emmy Awards for Outstanding Writing and two Daytime Emmys for Outstanding Program. In addition to this, Labine won a Writers Guild of America Award for each year that she wrote the show. After ratings began to sag, Labine was replaced by associate head writer, Mary Ryan Munisteri. ABC asked Labine back in early 1983 when it became apparent that Munisteri was not improving the ratings. Labine was fired once again, later that year. During her absence from Ryan's Hope, Michael Brockman, former president of CBS Daytime, asked Labine to develop a new serial in 1986. Her proposal was entitled Celebration but never made it to the air. In 1987, Labine was asked by ABC to come back to Ryan's Hope. She accepted ABC's offer and remained with the show until 1989, when the show was cancelled.
In 1993, Labine returned to daytime as head writer of ABC's General Hospital. She brought the show much critical acclaim, and won her seventh Daytime Emmy for Outstanding Writing for her work on the show. She chose to depart the show in early 1996. During this time, she created a proposed General Hospital spin-off, Heart and Soul, about two families, one black, one white, both show business families. The black family was three generations of jazz musicians. Next door was a theatrical family. The show was not picked up by ABC or NBC; Wendy Riche's competing Port Charles was ABC's choice instead.
Labine co-wrote, with Judith Pinsker, the 1995 New York Times bestseller General Hospital tie-in novel Robin's Diary, based in the AIDS storyline between characters Stone Cates and Robin Scorpio.
In 1996, Labine was offered the head writer role at As the World Turns but turned it down because she and her son Matthew Labine were trying to get HEART & SOUL [aka Union Place] on the air. "I had to turn it down because we were in the middle of that development. I said to Procter & Gamble, 'I am gratified by this offer, but if I have any chance at all...' I didn't think there was much chance but I thought it was worth a go to do our own show. And they were very lovely about it."
In late 1996, she was made head writer of ABC's One Life to Live because she had a year and a half left on her contract with ABC. She remained with the show until early 1998.
Most recently, Labine had a short stint at CBS' Guiding Light. She was head writer of the show from 2000 through 2001. Labine shared the reins of GL with her children, Matthew Labine and Eleanor Labine. Rumors abounded throughout Labine's tenure at GL that she, Executive Producer Paul Rauch, and Executive in Charge of Production Mary Alice Dwyer-Dobbin had frequent arguments about the show's direction.
At one point, it was announced in the soap press that the Labines were departing, only to have the announcement recanted a week later.  P&G did eventually replace the Labines the following year with writers Lloyd Gold and Christopher Dunn.
In November 2009, Labine gave WeLoveSoaps.net an exclusive interview during which she discussed her struggles with ABC during Ryan's Hope, her enjoyment of writing General Hospital, and her less enjoyable experiences on One Life to Live and Guiding Light. She discussed details about her aborted project, Union Place, and insights into her illustrious career.
Labine's died on November 11, 2016 at her home in Somers, Connecticut at the age of 82 from undisclosed causes.
Captain KangarooScript writer: 1966-1967
Where the Heart IsCo-head writer: 1971–1973
Script writer: 1970–1971
Love of LifeCo-head writer 1973–1975
Executive Producer: July 1975 – June 1982
Head writer: July 1975 – June 1982, January 1983 – November 1983, February 1987 – January 1989
General HospitalHead writer: September 1993 – March 1996
One Life to LiveHead writer: December 1996 – April 1998
Guiding LightHead writer: August 2000 – July 2001
9 Wins(1995; Outstanding Writing; General Hospital)
(1977, 1978, 1979, 1980, 1983 & 1984, Outstanding Writing, Ryan's Hope)
(1977, 1979 Outstanding Drama Series, Ryan's Hope)
12 nominations(1978, 1981 & 1982, Outstanding Drama Series, Ryan's Hope)
National Academy Of New York Arts And Sciences Silver Circle Recipient2000
Wins1995, General Hospital
1994, General Hospital
1980-1983, 1986–1989, Ryan's Hope
Nominations2001, Guiding Light
1996, General Hospital
1979, Ryan's Hope
Honored with Evelyn F. Burkey Award by the Writers Guild of America on February 19, 2005. The award was presented to her by friend and former Ryan's Hope star Kate Mulgrew.
Connecticut College Gold Medal 1995 Inherit The Earth Award for General Hospital story line on environmental racism, a ground-breaking plot for daytime about a trash incinerator about to be located in a low income area featured icon Laura Webber in fight for social justice .
Labine served the Writers Guild of America, East, as vice president for three terms, and is a recipient of the Richard Jablow Award for devoted service to the Guild.
She has been given Lifetime Achievement Awards by the New York Chapter of National Academy of Television Arts & Sciences and Soap Opera Digest.