An hour's brisk walk around the landscaped flanks of One Tree Hill - delighting in seasonal changes such as cries of newborn lambs or an avenue splashed by spring daffodils - has become a daily highlight for Mrs Tilby, who also plays golf and works as a personal assistant.
"I walk round the park and meet girlfriends and yet am still able to use the brain, occasionally.
"When I went back to work after raising two children, I walked at six o'clock most mornings. But now I work from home and the hours are flexible, it's whenever I want a break from my desk or have done everything. I just have to put my shoes on and go."
The park, with its 5km of paths, is like a family gym.
Mrs Tilby's husband, Paul, often accompanies her and she looks after two grandchildren while her daughter goes for a run through the park.
"I'm not a fitness fanatic but my level of fitness doesn't stop me doing what I want, though I do puff pushing myself up One Tree Hill.
"And when I build huts and play with the grandchildren, I think I'm slowing down."
She says Aucklanders are lucky to have access to farms without having to travel outside urban limits.
"It was pretty good bringing up kids in Auckland but I felt our kids were not as lucky as I was on a farm.
"But they spent holidays on a farm with cousins and our grandchildren go to the Ambury Farm Park and feed orphan lambs with their kindergarten group."
Royal Oak is a central launching pad for the Tilbys' town and country adventures.
"Auckland has a lot to offer."
They explore volcanic cones, west coast beaches and on Sundays catch up with the changes in the inner city, with new building and modern treatments given to streets they recall from their youth.
Sometimes, city traffic jams prompt thought of retirement in a place where roads are not as busy.
"But if we were to move away now we would just become old people," said Mrs Tilby.
"I think the fact that we are in a busy environment and with heaps to do and our friends are still here makes this our place to live.
"My mother-in-law, Kathryn, is a tonic for me.
"She's enjoying Auckland.
"At 84 she is still very active and drives herself to the airport and to St Lukes Mall. "I think if she can do it, I may be able to at her age too."
• Read the first two stories in this series here: tinyurl.com/akllovefamily.
