The men, who were armed with a sawn-off shotgun, tried to kick their way through before noticing the bank manager and Donnelly in the office.
"One of them came barging in but instead of asking (the bank manager) to open the back he saw my handbag and he said 'give me your money' and I said 'no', and I screamed."
The man grabbed the bag, which contained about A$400 ($509) and Donnelly's passport, but she refused to let go.
"He dragged me out of the office on to the floor outside and I stood up and started screaming and screaming. Everyone in the supermarket next door could hear it, which put (the robbers) off.
"Another woman who was in the bank... told me she was terrified. She said, 'I was thinking please don't scream any more, he's going to shoot both of us'."
One of the frustrated robbers gave Donnelly a shove on the way out.
"(The bank manager) said I saved the place from being robbed. She said she froze."
Donnelly was recovering from bout of bronchitis at the time, and she said the shock of the incident had given her pneumonia, for which she was in hospital for several days.
Detective Sergeant Jason McIntosh said the two men took a stolen Nissan Bluebird across town to Pakuranga where they entered a Westpac bank and demanded cash.
McIntosh said they made off with $8250 and dumped the car nearby.
Bob John Heke, 25, was arrested on Friday and appeared in Auckland District Court yesterday charged with aggravated robbery, assault with intent to rob and unlawfully taking a motor vehicle.
He was remanded in custody and is to appear again next week. Another man has also been charged although the courts could not release the details yesterday.
But police are appealing for witnesses to the robbery of a security van outside the same Lynfield ASB.
Security staff were robbed at gunpoint by two men about 6.20pm Friday.
The offenders stole a container and fled in a silver Nissan that was recovered shortly afterwards.
The men, armed with a shotgun and an assault rifle, were wearing overalls and masks. A third man who was driving the vehicle was described as a heavily-built Maori or Polynesian in his early 20s.
Anyone with information can contact 0800 555111.