"But when I found myself on the motorway last night having been called to an emergency and the motorway was blocked I wasn't sure at first what to do.
"Then it came to me possibly contacting police might be the answer."
She thanked Malcolm and Morgan for their "amazing" response to help her perform surgery on a "desperately unwell" child.
"You were just so positive and took the anxiety from me, and the tones in your voices where you were obviously just going out of your way to help - you have no idea the difference that made," she said.
Rumball called the station to let them know the baby had survived the surgery.
"Our staff were very happy we could help Elizabeth in any way to carry out her work. It is great when we can work closely with our partners to get the best possible outcome," Counties Manukau police said.