The Wagga local, who was born Joan Driscoll, turned 100 on Wednesday, after spending the weekend celebrating her imminent milestone in the presence of generations in the family.

It was a trifecta weekend though, with two other members of the family also celebrating big birthdays in close proximity.

"Her sister is turning 90, and my oldest sister is turning 80, and it was all on the Queen's birthday," said son Simon Lewis.

"The Monday was also my partner's birthday."

It meant that the family was singing happy birthday on repeat nearly the whole day, as led by granddaughter and professional singer, Beatrice Lewis.

The momentous occasion also led to an influx of mail from all over the world.

"The Queen, the prime minister, the premier and the local member all wrote to congratulate her," said her son.

"She was more concerned with her family all being there."

With three generations represented in the room, it was a re-union.

"She always responds well to faces, and she really picks up when she sees her family," Mr Lewis said.

Born in the aftermath of the First World War, Ms Lewis attended Woodend School west of Yerong Creek.

Described by family by her son as a 'country girl at heart', Ms Lewis' family owned and operated a small farm in the town.

However, her days on the land were number when in high school she travelled to Sydney to live with her grandmother and attend St Patricks High School at The Rocks.

She returned to the farm at age 16, when her mother died. She took on the care of six other siblings, along with her older sister Mary.

A trained nurse, Ms Lewis was working at the Coast Hospital during the attempted Japanese invasion of World War II.

A submarine attempted to knock out the Bunerong power station nearby, which caused the evacuation of the hospital.

"They were firing over the Coast Hospital which prompted everyone to flee to the bomb shelters," said son Simon Lewis.

"Except Joan Driscoll who would have remained asleep in bed, if it was not for her cousin who noticed her missing.

"She made it to the shelters OK, but only to realise she had forgotten her rosary beads which necessitated a dash back to get them."

Later in life, she married Dr Lewis, a widower with four children.

With her own two children, the two families united to form a strong unit.

"My dad delivered half of Wagga," said son Simon.

"A lot of people would have remembered him."