"She was very badly injured but the baby was fine."
He said the woman has stab wounds on her face, head, hands and back, but the baby was uninjured.
"She was kind of unconscious but she was responding until the ambulance arrived, so we just kept talking to her."
Pangly said other bystanders also rushed to the woman and used nappies from the dairy to try and stem the bleeding.
"I held the baby from her first, then someone else took the baby form me and I was helping he lady. Two or three ladies came and were helping, too."
In a statement, police said the 31-year-old woman was taken to Middlemore Hospital in a critical condition. Her condition was later downgraded to serious and her injuries are not believe to be life-threatening.
A 16-year-old boy was also taken to hospital with moderate injuries.
The scene was cordoned off for a time and motorists were asked to avoid Willis and Kelvin Rds and Sheehan Ave.
There was no risk to the public, the statement said.