Daphne said the trip was "absolutely fantastic".
"It was just such a joy. They took me everywhere that I used to take them," she said.
Having visited a number of zoos around the world, some with "horrendous conditions", Daphne said she thought Auckland was one of the best.
"The zoo has been improved over the years absolutely beyond comprehension.
"Continual upgrades over the years have been very gratifying, I'm such an animal lover and I hated to see animals in such unhappy conditions."
To celebrate its 90th birthday this month, Auckland Zoo is giving anyone over the age of 90 free entry this month until Christmas.
Anyone over 65 is also being offered an entry price of $9 to celebrate the milestone.
Auckland Zoo director Jonathan Wilcken said the move acknowledges the "huge part" of the zoo's history these generations have played.
"Many visited as children and then as adults with their own families, so we want to acknowledge this support," he said.
Wilcken said the zoo hoped people who hadn't been in a while would be encouraged to visit.
"Auckand Zoo has changed enormously over the past nine decades," he said.
Communications manager Jane Healy said senior citizen visiting numbers have been up 42 per cent since the promotion began at the start of the month.
She said people still have time to come and take advantage of the offer and see the big changes Auckland Zoo has undergone in the last few years.
"It's been nine decades in the making.
"Last year we opened Te Wao Nui which was the biggest development in our history. It celebrates and focuses on New Zealand national treasures - highly appropriate given we're coming into our 90th year."
Since 1923, Auckland Zoo has had over 28 million visitors.
Ninety years of Auckland Zoo:
* Auckland Zoological Park is officially opened on 17 December 1922 by Governor General, Viscount Jellicoe
* The Old Elephant House is built in 1923 to house the Zoo's first elephant Jamuna, who arrived in 1923 from Calcutta. The Old Elephant House is now used as a function centre
* Elephant Jamuna passed away in 1965 leaving the Old Elephant House empty until the arrival of Kashin in 1973
* The first giraffe to be born in New Zealand is born at Auckland Zoo in 1965. He was named Peter after Olympic gold medallist Peter Snell
* Chimpanzee Janie arrives from Regents Park Zoo in London in 1956 with fellow chimpanzees Bobbie Josie and Minnie. Janie is now is the Zoo's oldest animal resident at age 58
* Auckland Zoo welcomes giant pandas Xiao Xiao and Fei Fei for a three-month stay from China, attracting 300,000 visitors
* Beloved elephant Kashin passes away on August 24, 2009 and 18,500 Aucklanders come to the zoo to see her off
* Auckland Zoo opens its largest ever exhibit Te Wao Nui, a $16 million New Zealand precinct which takes up one fifth of the zoo
- nzherald.co.nz