McGarrigle last performed six weeks ago alongside her children in London
Canadian folk singer Kate McGarrigle has died of cancer at the age of 63.
The mother of singers Rufus and Martha Wainwright, McGarrigle died at home in Montreal on Monday. She had been battling cancer since summer 2006.
Kate rose to prominence with sister Anna when they recorded together in the 1970s. "Sadly our sweet Kate had to leave us last night," Anna said.
"She departed in a haze of song and love surrounded by family and good friends," she wrote on their website.
"She is irreplaceable and we are broken-hearted. Til we meet again dear sister."
The pair first attracted attention in 1974 when Linda Ronstadt recorded their song Heart Like a Wheel as the title track for one of her albums.
The sisters' first record came out in 1975, titled Kate and Anna McGarrigle, and brought them critical acclaim.
Rufus Wainwright recently cancelled an upcoming tour due to a "family illness"
Other artists who covered the pair's songs included Emmylou Harris, Billy Bragg, Kirsty MacColl, Judy Collins and Elvis Costello.
"Kate was a folk singer through and through, a bi-lingual Canadian who celebrated her heritage and drew on it for songs that were to become standards on the folk scene," said BBC Radio 2 folk show host Mike Harding.
"It is tragic that she has finally lost her fight with cancer - she was a beautiful and rare human being."
Kate McGarrigle and her sisters - she had another called Jane - grew up in a mountain village in Quebec.
Kate's own songs included The Work Song, Cool River and Lying Song.
She was was once married to fellow folk singer Loudon Wainwright lll and received the Order of Canada in 1994, one of the country's highest honours.
'Warmth and feeling'
BBC Radio 2 host Bob Harris described her music as "very human".
"Through the years, I've played Kate and Anna McGarrigle's music on my programmes and really loved the warmth of their music.
"When she sang in French there was a warmth and a feeling to it that kind of transcended language in some way and communicated anywhere."
McGarrigle made her last public appearance six weeks ago at a concert with Rufus and Martha Wainwright at the Royal Albert Hall in London.
The show raised $55,000 (£33,600) for the Kate McGarrigle Fund, which she set up in 2008 to raise awareness of sarcoma, a rare cancer that affects connective tissue such as bone, muscle, nerves and cartilage.