McGarrigle's brother-in-law, Dane Lanken, said the singer died at her Montreal home Monday night surrounded by her sisters, Jane and Anna, and her children, Rufus and Martha Wainwright, also singers.
He said McGarrigle had been battling cancer since the summer of 2006. He said the cancer started in her small intestine and spread to her liver.
Kate and Anna, known as the McGarrigle Sisters, began their careers performing at Montreal coffeehouses in the 1960s with a group called the Mountain City Four. They got their break in the 1970s, when their songs were covered by numerous artists, including Linda Ronstadt, who used "Heart Like a Wheel" as the title song to one of her albums.
In 1975 they made their first record, "Kate and Anna McGarrigle," which brought them critical acclaim and additional famous covers by artists including Emmylou Harris, Judy Collins and Billy Bragg.
Their own well-known releases included "The Work Song," "Cool River" and "Lying Song."
Kate McGarrigle received the Order of Canada in 1994, one of the country's highest honors.
McGarrigle was once married to American singer-songwriter Loudon Wainwright III. Her son, Rufus Wainwright, recently canceled an upcoming tour, citing an illness in the family.
Born in Montreal, the famous singing duo grew up in the Laurentian Mountains village of Saint-Sauveur-des-Monts, Quebec. There, they learned the piano from the village nuns.
Caption: In a Monday, April 21, 2008 file photo, singer Kate McGarrigle arrives at the opening of Donizettis opera La Fille Du Regiment and the Metropolitan Opera opening night gala benefit at Lincoln Cente in New York. Internationally acclaimed folk singer Kate McGarrigle, best known for performing with her sister Anna, died of cancer Monday, Jan. 18, 2010 at her Montreal home, said her brother-in-law, Dane Lanken. She was 63. Peter Kramer, File / AP Photo
Note From Rufus Regarding Kate McGarrigle
When inevitably I read today in the papers that my mother lost her battle with cancer last night, I am filled with an immense desire to add that this battle, though lost, was tremendously fruitful during these last three and a half years of her life. She witnessed her daughter's marriage, the creation of my first opera, the birth of her first grandchild Arcangelo, and gave the greatest performance of her life to a packed crowd at the Royal Albert Hall in London. Not to mention traveling to some of the world's most incredible places with both my sister, her husband Brad, my boyfriend Jorn and myself. Yes, it was all too brief, but as I was saying to her sister Anna last night while sitting by her body after the struggle had ceased, there is never enough time and she, my amazing mother with whom everyone fell in love, went out there and bloody did it. I will miss you mother, my sweet and valiant explorer, lebwohl and addio. X
In 2008, Kate established the Kate McGarrigle Fund in association with McGill University Health Centre, the Jewish General Hospital through the MUHC Foundation, the Cedars Cancer Institute, and Cancer Research UK in order to raise money and awareness for the fight against this rare type of cancer. If you would like to make a donation in honour of Kate, please follow this link below and donate online or call the MUHC Foundation directly at +1-514-931-5656.
Kate McGarrigle Fund donation website: