But Canberra's Gladys, Lady Harders is one such person. And as is tradition, Lady Harders' family has put in a request for a 100th birthday message from the Queen.

This is despite Lady Harders being a devout republican.

"I'm not on the Queen's side," Lady Harders says.

"But I have always followed the news of the royal children in the paper and all that sort of thing.

"So I kept up with them and watched them grow up and get married and have children and all that sort of thing."

Lady Harders has witnessed a lot in her 100 years on Earth.

As wife of Sir Clarrie Harders, who is best known as the Attorney-General's Department secretary in the 1970s, she has been a fly on the wall for more notable moments in history.

She was there when Sir Clarrie received the call telling him that then-prime minister Harold Holt had disappeared while swimming.

And the day after former prime minister Gough Whitlam was dismissed in 1975, Lady Harders was there when he called Sir Clarrie about the situation.

However, Sir Clarrie said he wasn't able to help because, as the Attorney-General's Department secretary, he needed to support Malcolm Fraser.

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"I couldn't believe it. He'd been so friendly with him and I just thought 'This can't be happening'. But my husband was a man of character," Lady Harders says.

"I liked Whitlam. He was my husband's favourite and it was difficult because he had a great unlike, with many of the Australian people. But I thought he was a nice man. He had tremendous wit which was incredible.

"And his wife Margaret was a great delight. She was very nice to the ladies that went away with them. She was helpful."

In the years leading up to Whitlam's dismissal, Sir Clarrie and Lady Harders had travelled with the former prime minister to the United Kingdom and even dined at 10 Downing Street with the British prime minister.

Lady Harders often travelled with her husband on business trips, taking the opportunity to learn from other countries and cultures.

"It was interesting for me. Most of the time I sat in the corner but I was an observer," she says.

"I learned as much as I could about the country and the people. I drew a lot on that over the years. You don't remember it all but you have little ideas or little things that happened that were interesting."

While Lady Harders has spent her life travelling the world, Saturday will see her family travel to her to celebrate her 100th birthday with a special morning tea.

"A week or so ago only half of the people could be here because of these border closures," Lady Harders says.

"Now I'm so pleased they all can come. Some of the little ones I haven't seen since they were babies more or less and now they're at school and do all sorts of interesting things."