"It was the depression. Most simply could not afford to get married. Times were hard, you had to just keep a job. We were rather fortunate; most people were worse off than us," she said.
Her father was a sea captain, which allowed her mother to remain at home with her children, rather than having to find work like most other women of the day.
It still wasn't easy and she remembered the rationing - "You got a pound of butter a week" - although her father managed to get a little extra.
They read avidly about World War 2 from 1939 to 1945, especially her mother, who had a brother serving overseas.
"She used to read the paper all the time to see if his name was mentioned," she said.
And how things had changed in her lifetime. "We had buggies and traps, no motor cars," she said.
"Bakers and butchers delivered with a horse and cart, there were no supermarkets. The grocer would come once a week for your order."
And for all the hardships of her early life, times had got worse; "Kids seem to grow up so quickly."
Kathleen, mother of one, grandmother of five, great-grandmother of eight, was married to a builder, who built their first home, still standing in Owens Rd, Epsom, and was well used to making do with what she had, including making clothes "out of the old and that."
Robert passed away in 1972, and, having not met anyone else she wanted to marry, she moved to the Far North 20 years ago, with son David when he retired.
Living in the North had been a big change but she had made a lot of good friends.
"Everyone is nice and friendly up here."
She wasn't especially impressed about becoming a centenarian - "I suppose it's an achievement; everybody else seems to think it is," she said, but receiving cards from the Queen, the Governor-General and the Prime Minister was "very nice."
She credited a good home and upbringing, and a good diet, for reaching the milestone. She had no time for "dried stuff" or microwaves, and only enjoyed a little bit of wine at Christmas and birthdays. And she's always enjoyed a good memory, "But I'm starting to lose a bit."
Meanwhile her birthday was celebrated at Switzer, where she has been a resident for just over a year, and where she is clearly held in affectionate regard.
"They're good to me, especially Margaret (McQuade). They say I'm a good patient," she said.
Margaret replied that the privilege was all hers.
"She is an amazing person, a great example of a 100-year-old," she said.
As for Kathleen, she believed she had been very fortunate.
"I've had a lovely life," she said.