Mrs Souness was joined at her 100th birthday lunch in Waihola by 31 members of her family, representing five generations.
"I have no idea what my secret is.
"A happy childhood ..."
One of four children, Mrs Souness grew up in Maheno on a farm with a river running through it, and cousins living next door.
She married Allan Souness - her neighbour - in October 1934, aged 24, and had seven children: Alison, Lindsay, Myra, Ruth, Kathleen, Gordon and Claire.
"They kept me young.
"A two-storey house, going up and down all those stairs kept me fit," she said.
The Souness family moved to Milton in 1968 "to retire from the farm", Mrs Souness having earlier trained as a nurse in Oamaru.
She had seen many changes over the past 100 years, including the arrival of washing machines, cars and planes, she said.
"My sister and I hid under the bed when the first aeroplane flew over, we were so scared."
The first car to come to Maheno belonged to a Dr Orbell, of Oamaru, she said.
"Allan was asked to go and show him where to go, because there were no phones."
Mrs Souness travelled to school by cart, drawn by a pony, which she had to catch and then gear up to the cart each morning.
Her youngest daughter, Claire, said Mrs Souness was a talented lady who had worked hard all her life.
"She is very respected and loved.
:And a legendary baker."
"I'm just an ordinary mother," Mrs Souness said.
"Life just goes on like most people's lives do - it has its ups and downs."