She had taken inspiration from Mary Johnson, who she worked alongside for years, and who carried on into her late 70s, only calling it a day when a "crook" knee got the better of her.
She and her late schoolteacher husband Wayne had moved back to her childhood home from Twizel, and Katie now lives with her daughter, just off the Waipapakauri Straight.
That makes for a short commute to work, although until recently she had headed into Kaitaia to begin her day with a gym workout. And she's still got the energy to get stuck into her garden at the end of her working day.
She knocked off early on Friday, after receiving flowers and a cake (with just the one candle) from her workmates, but she was back on deck yesterday.