Footage released by Auckland Transport showed the woman was missed by centimetres as she appeared distracted while on the crossing.
Auckland Transport rail services manager Craig Inger said it was "disturbing" two men and a woman with her dog also crossed the tracks while the lights flashed.
He said: "We’ve checked the footage of this morning’s incident and we can see the woman checked to her right before crossing but not to her left and that’s where the train was coming from. “It’s really important that that you check both directions before crossing, a train can come from either direction.
"The lights and bells mean don't cross."