Ordinary People. Enough said.
Their story
Mary Tyler Moore was born on 29 December 1936 in Brooklyn Heights, New York, the first child of Marjorie (nee Hackett) and George Tyler Moore. She grew up partly in Flatbush and Flushing before the family moved to Los Angeles in 1945, when she was eight, at the urging of…
Mary Tyler Moore was born on 29 December 1936 in Brooklyn Heights, New York, the first child of Marjorie (nee Hackett) and George Tyler Moore. She grew up partly in Flatbush and Flushing before the family moved to Los Angeles in 1945, when she was eight, at the urging of an uncle who worked for MCA. She attended Saint Ambrose School and Immaculate Heart High School in Los Feliz. The household was difficult: both parents struggled with alcoholism, and she and her siblings were sometimes cared for by relatives. Her younger sister Elizabeth later died of a drug overdose at 21; her brother John died of kidney cancer at 47.
She entered television in 1955 as "Happy Hotpoint," dancing as an appliance elf in commercials that ran with The Adventures of Ozzie and Harriet. Brief modelling and guest roles followed. On Richard Diamond, Private Detective she played Sam, the glamorous switchboard operator heard but almost never fully seen, until she asked for a raise and was fired. Carl Reiner, with a nudge from Danny Thomas, cast her as Laura Petrie on The Dick Van Dyke Show (1961-1966). At 24 she became an Emmy-winning comic partner to Dick Van Dyke, famous for fitted capri pants, physical comedy, and a modern suburban wife who still felt like a peer rather than a punchline.
With second husband Grant Tinker she co-founded MTM Enterprises in 1969. The Mary Tyler Moore Show (1970-1977) made Mary Richards, an unmarried associate producer at a Minneapolis TV newsroom, one of the defining working women of American television. The series spent years in the top ratings, won a then-record haul of Emmys (later surpassed by Frasier), and spun off Rhoda, Phyllis, and the drama Lou Grant. Its theme song promised that love was all around; its famous hat-toss opening became a Minneapolis civic landmark when a statue of that moment was unveiled in 2002.
Beyond the sitcom she took risks. Film work included Thoroughly Modern Millie (1967) and Change of Habit (1969) with Elvis Presley. Ordinary People (1980) earned her an Academy Award nomination for Best Actress as a grieving, tightly controlled mother. On stage she won a Special Tony Award for Whose Life Is It Anyway? (1980). Television movies such as First, You Cry, Heartsounds, Lincoln, and Stolen Babies (another Emmy) extended her dramatic range. MTM Enterprises became a quality-TV powerhouse (The Bob Newhart Show, WKRP in Cincinnati, Hill Street Blues, St. Elsewhere, and more) before its later sale.
Private life brought lasting pain and later steadiness. She married Richard Meeker in 1955; their only child, Richard Carleton Meeker Jr. ("Richie"), was born in 1956. After divorcing Meeker she married Tinker in 1962; they separated and divorced by 1981. Richie died on 14 October 1980 of an accidental gunshot wound at 24, weeks after Ordinary People opened. In 1983 she married cardiologist Dr. S. Robert Levine; they remained together until her death. Diagnosed with type 1 diabetes at 33 after a miscarriage, she became International Chairperson of JDRF and later the namesake of the "Forever Moore" research initiative. She entered the Betty Ford Center in 1984, got sober, quit a heavy smoking habit, and co-founded Broadway Barks with Bernadette Peters. She wrote the memoirs After All (1995) and Growing Up Again (2009).
Across a career dated 1955 to 2013 she won seven Primetime Emmy Awards, three Golden Globe Awards, and two Tony Awards, and the 2012 Screen Actors Guild Life Achievement Award, presented by Dick Van Dyke. She is the American television actress Mary Tyler Moore, not the British actor Sir Roger Moore.
Moore died on 25 January 2017 at Greenwich Hospital in Greenwich, Connecticut, aged 80, of cardiopulmonary arrest after contracting pneumonia (she had been on a ventilator the week before). A Connecticut death certificate, reported by TMZ and other outlets, listed aspiration pneumonia, hypoxia, and diabetes mellitus among contributing conditions. She was buried privately at Oak Lawn Cemetery in Fairfield, Connecticut. Tributes from Dick Van Dyke, Ed Asner, Oprah Winfrey, and countless colleagues stressed that she had changed what a woman on television could be, and that she really had turned the world on with her smile.
Biography adapted from English Wikipedia (CC BY-SA) Mary Tyler Moore; New York Times obituary (2017-01-25); Variety obituary; AP / amNewYork death-certificate reporting; Page Six / TMZ death-certificate coverage; Hollywood .
In their own words
“I knew at a very early age what I wanted to do. Some people refer to it as indulging in my instincts and artistic bent. I call it just showing off, which was what I did from about three years of age on.”
Archive of American Television interview, Diane Werts, 1997 (Wikiquote / Television Academy).
“Pain nourishes courage. You can't be brave if you've only had wonderful things happen to you.”
Widely quoted; Reader's Digest / Wikiquote.
“Take chances, make mistakes. That's how you grow. Pain nourishes your courage. You have to fail in order to practice being brave.”
Cited in Winning Words (Allen Klein) / Wikiquote.
“I'm not an actress who can create a character. I play me.”
TV Guide (1970) / Wikiquote.
“My grandfather once said, having watched me one entire afternoon, prancing and leaping and cavorting, 'this child will either end up on stage or in jail.' Fortunately, I took the easy route.”
Archive of American Television interview (Wikiquote).
“Whatever it is, it's OK because it's what it is. Don't be looking for perfection.”
Career retrospective interview coverage / Wikiquote (punctuation normalized; no em dash).

That quote of hers about playing herself, not creating a character, says everything about her integrity.