Later that evening she attended a fortnightly training session for the Emergency Response team.
She joined the team about five years ago, influenced by her grandfather who had been a prisoner of war in World War II.
"He said the Red Cross packages they got had saved his life," Ms Montgomery said. "When I saw the opportunity [to join Red Cross] come up in the paper I had no idea what to expect and found myself confronted by these two guys in bright red overalls watching a disaster video. I thought, 'What have I got myself into'?"
Ms Montgomery started doing welfare work for the emergency management team. When the first earthquake happened in Christchurch last September she paired up with her teammate, Heather Blandford. The two formed such a close bond they have become "like sisters now".
They did 12-hour shifts at the Addington Welfare Centre, where there were about 300 people at the centre at any one time. "It was surreal - we got so much respect.
"September was an adventure - no one died, it was everything we had trained for. I still believe it was our practice run."
Her bags are always by the front door, packed and ready to go. One holds protection gear and the other is a "grab bag", loaded with her personal effects.
But nothing prepared her for the February earthquake.
"I was at work when Red Cross called me to get ready and I had 48 hours to psychologically prepare. In September we had four days.
"The airports were still closed. It was my daughter's birthday the next day. I just thought, 'Far out'."
When the Hawke's Bay team arrived in Christchurch one of the first things she remembers was seeing "the sheer terror on people's faces".
And the aftershocks: "We were just rocked left, right and centre by these aftershocks - we would hear them coming and would just brace ourselves. But it was amazing support down there. There were teams from all over New Zealand and we'd met everyone before." It was also an emotional time. "Sometimes I had to excuse myself and I would go and just burst into tears and cry.
"September definitely changed me, who I am as a person and my outlook on life. I became more dedicated, knowing that what we did made a difference - in a humble way," she said.
It has made her even more passionate about her work. "It's so diverse: I was called out at 5am in April to go to the flooding at Haumoana, then later I managed the welfare centre at Waipukurau to help with the evacuations from the badly affected coastal area. You get out what you put in."