While Lauren frantically searched for an emergency stop button, the train began to move, as her daughters chased the train crying.
"I told the train guard we had to stop the train and said she was sorry, before disappearing up the train to obviously notify someone else," said Lauren, who was also crying at that point.
"I didn't see the train guard again until I got to Porirua station and she didn't say anything to me.
"No one took my name or number, or could offer me anything more than when the next train would be able to take me back."
Having phoned police, Lauren's fear lessened when they confirmed they could see the girls on the platform through CCTV cameras.
"Luckily, a very kind member of the public offered to take me and my 1 year old back to Paremata Station."
By the time she returned, around 25 minutes later, a member of the public was standing with the girls.
"Fortunately, when the girls were chasing the train, there was no serious incident. What concerns me is why a train guard can't stop a train in an emergency situation."
According to Lauren, who was contacted by TransDev with an apology last night, she was told the train guard was new.
TransDev customer and communications manager Emily Liddell said staff had not taken Lauren's details because their full focus was on reuniting her with her children.
"At the time, the train manager contacted our Service Control Centre, who then kept an eye on the children through the cameras at Paramata Station, and contacted the police."
Ms Liddell said a full investigation was launched yesterday evening.
"Senior management is involved with this investigation, which includes onboard service, security and training."
TransDev admitted there was an emergency stop lever that staff should have used in this instance.
"Our staff receive training on how to deal with a range of scenarios, including situations that might require the train to stop immediately.
"We are reinforcing the expected response from our staff in a situation like this and doing everything we can to prevent it from happening again."
Lauren said she would like to see changes made to Metlink's policy.
"They need to have a number of systems put in place."