Key Points:

Julie Winnefred Bertrand, believed to be the world's oldest woman at 115, has died in her sleep in a Montreal nursing home.

Bertrand was born September 16, 1891, in Coaticook, Quebec, and became the world's oldest woman last month, after the death of Elizabeth Bolden, a Tennessee woman born on August 15, 1890, according to the Guinness Book of World Records.

The eldest of six children, of harness maker Napoleon Bertrand and his wife, Julia Mullins, Bertrand never married.

She worked as a buyer for the FX Lajoie department store in Coaticook, a mill town close to the Quebec-US border.

For the past 35 years, her home had been a small room at Residences Berthiaume de Tremblay, a long-term care facility. Until 10 years ago, Bertrand enjoyed full health and a quiet life, punctuated by the home's social events, picnics, singalongs and her annual birthday party.

Emiliano Mercado del Toro of Puerto Rico, the world's oldest person, who was 26 days older than Bertrand, died on Thursday at his home on the northern coast of Puerto Rico.

He was drafted into the US Army in 1918 but did not serve in combat because World War I ended while he was still in training. Later he worked in the island's sugar cane fields.

He was married three times but never had children. A 114-year-old Connecticut woman, Emma Faust Tillman, is now believed to be the oldest living person. She was born November 22, 1892.