Rankin, who went on to a solo career after being part of the famed The Rankin Family singing group, was first diagnosed with breast cancer in 2001. The disease resurfaced in 2009 and in 2011 she was diagnosed with liver cancer.
Rankin released "All the Diamonds" this year, her first solo effort in seven years.
The Rankin Family, comprised of her and her four siblings, performed for 10 years, selling more than 2 million records. The group won six Juno awards and three Canadian Country Music Awards.
The Rankins grew up in the Cape Breton village of Mabou.
Rankin is survived by her husband and son.
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