Along with her mother Irene, Denise took baby elephant Sheila in to her north Belfast home after it escaped an order to euthanize some of the more dangerous animals at the zoo.
Nine lions, two tigers and a number of bears and wolves were killed on the orders of the Ministry of Public Security because of fears that they would escape and threaten the public if the zoo was damaged in a German bombing raid.
Earlier this week the zoo — which is celebrating its 75th anniversary — launched a campaign to find the mystery owner and, through a surviving relative, have found more information on her identity.
Her second cousin, David Ramsey from Belfast, described her as an “eccentric” lady who lived in an exotic home in north Belfast called Loughview House.
Mr Ramsey also said that Sheila the elephant only lived with Ms Austin in the evening.
He said: “When the Head Keeper, Dick Foster, left work, Denise took Sheila from her enclosure, walked her a short distance to her house at Whitewell Road, and walked her back up to the zoo in the morning, sometimes stopping at a shop, the Thrones Stores, on the Whitewell road for stale bread.
Sheila managed to stay hidden due to the large walls which surrounded the house, and zoo staff were not aware of her second home until she chased a dog into a neighbours garden, breaking the fence.
Neighbours brought the incident to the attention of the Head Keeper, whereupon Sheila had to remain in the zoo. Denise continued to visit Sheila in the zoo, particularly at night during Luftwaffe air raids, when she rubbed her ears to keep her calm.
Ms Austin died in 1997, but her cousin said he believed she would have been “tickled pink with all the attention”.