And although being mouthy and fun were the first two reasons given by the show's producer for her selection over female archaeologists with UK accents, the most important reason was that she had already paid her dues by years of study and tireless fieldwork.
Gallagher's life around artefacts and museums had given her a keen appreciation of how her childhood hometown of Tauranga still lacked the symbol of a city's ''spiritual wellbeing'' - a museum.
The closest thing Tauranga used to have to a museum was the Historic Village which she remembered as a fun day out with her mother.
Gallagher said museums were a reflection of stability, but with so many people still pouring into Tauranga, the city had never reached that point.
''We have the most amazing stories to tell.''
The turbulent history of land confiscations had strained race relations and had still not healed, she said.
''Now we have a new surge of people wanting to make the most of their money from selling in Auckland. What connections would they have to a museum here,'' she asked.
Gallagher spent the first eight years of her life living in Ngatai Rd, Ōtūmoetai, before her mother decided to study to be a social worker and shifted to Papatoetoe. The South Auckland suburb was a microcosm of her interest in human cultures.
''When I was there it was quite Pākehā and then it became quite Polynesian and Maori and now it is quite Indian.''
Central to Gallagher's early life was her mother's family and holidays at the family bach in Waihi Beach - she never knew her father.
An early memory was staying with her great uncle at the bach and collecting kaimoana. Afterwards, the shells would always be returned to the beach - a memory with powerful connections when she began Māori Studies papers at Auckland University.
Gallagher's formative years were dominated by spending a lot of time in the company of her aunties - there was only one brother in her mother's large family.
She was introduced to storytelling from a young age, absorbing what the adults were saying as she poured the tea and passed around cakes.
''It was a very matriarchal family.''
The stories stretched all the way back to the family's roots in an Irish village, with a couple of her great aunts born in the first decade of the 20th century filling in the details.
She heard about the hardships of carving farms out of the bush around Raglan after World War I.
''The storytelling really stuck. I was an only child to a single mother and I was brought up by all these women and their husbands.''
Gallagher also credits her mother with being a big influence on her future.
''History books and art history books were always around the house.''
One book that particularly caught her imagination dealt with the excavation of the ancient Roman city of Pompeii that was buried by the eruption of Mt Vesuvius in 79 AD. The book showed how history could be unravelled by science - mining the past using forensics.
''It was about piecing together all the different bits of information to create a story.''
She did not realise it at the time, but this pointed directly to the reason why Time Team was so popular.
In her early teens, Gallagher became intrigued with the forces that shaped the earth and how they impacted the human race.
''The whole thing was working towards a multi-discipline approach to how we view history. We have the history but what is history without the land.
She developed a special interest in geomorphology or the shape of the land, such as how erosion affected settlements - something very pertinent to the shoreline of Tauranga Harbour today.
Gallagher volunteered to catalogue taonga (Māori treasures) at Auckland Museum in her second year at university, eventually leading to a paid job one day a week working on the conservation of some wonderful objects.
She said described Māori Studies as a ''complete parable with my Irish background of a big family, storytelling and keeping connections with the land alive''.
Gallagher said the most amazing thing with Māori Studies was learning how to make things using traditional methods. ''That was so awesome.''
Her university studies in anthropology and physical geography headed her in the direction of becoming a conservator.
''You can't have a museum without conservators.''
Gallagher's arrival in the UK in 1998 marked three years of intense work as a contract archaeologist, a steep learning curve in which she bounced around a circuit of different digs.
''At first, I had no idea what I was doing. It was only the good graces of people taking me under their wing ... I just asked questions.''
She had the good luck to dig up a small intact collared ceramic urn early on in her life as a circuit archaeologist. ''Everyone thought it was amazing.''
Another abiding memory was how cold it was at digs, balanced by the joy of working with a great bunch of people.
''We were all very poor, working with great archaeology. They were good times with far too many drinks.
''Field archaeology is a very tactile thing. You have got to use all your senses - a sense of feel and eyesight, and being methodical. It is literally about the way you peel back layers of history.''
Gallagher quipped that she qualified as a master of dirt. The skill of an archaeologist was to look at soil and dirt, think about its size, compactness, what other kinds of dirt were in there and how it got there.
After three years around digs, she decided to advance her passion for conservation by enrolling as a full-time student at Cardiff University. She ended up teaching archaeology in the university's lab until the pull of her favourite place in the UK, Bristol, proved too strong to resist.
She got a job working for the city's archaeological unit and spent half a day a week volunteering at the museum. It was through these contacts and that the nucleus of the people fronting Time Team came from Bristol, that her name came up.
Producer Tim Taylor was thinking that Time Team had become a bit male heavy and Gallagher had been doing a bit of behind-the-scenes research for the show.
Despite her initial reservations that Time Team was not her cup of tea, she was selected over English archaeologists because she was mouthy, fun and had the knowledge needed to get information across to viewers.
The rest was history. She spent a week of every fortnight working on Time Team for seven years, from April to October.
Her growing reputation in the UK led to her appointment as lead conservator for four seasons at Catal Hoyuk, a Neolithic site on Turkey's Anatolian Plains inhabited for about 2000 years from 7500 BC. It revealed the first evidence of the domestication of wheat and cows, with the discovery of incredible ceramic wall paintings.
Gallagher said the residents of Catal Hoyuk used the landscape in a very similar way to how Māori, a Neolithic culture until the arrival of Europeans, used the landscape in New Zealand.
Now that her focus in life was squarely back in the Bay, she and partner Raysan Al-Kubaisi had bought the family bach at Waihi Beach and were gradually modernising it from being a series of add-ons.
And the successful formula of adding dramatic tension to TV shows by putting time limits around the storyline had been adapted to a TV series filmed in New Zealand called Heritage Rescue.
Gallagher fronted the show in which small community run museums were given five-day make-overs to turn around patronage. The third series was in post-production.
She was acutely aware how archaeology was everywhere around Tauranga Harbour and the hills surrounding the harbour - pointing out how a Māori pa once thrived on the scene of the interview with the Bay of Plenty Times Weekend - the reserve at the end of Park Rd.
Gallagher had just emerged from walking the route of a planned harbourside walkway that in all likelihood would turn up archaeology.
The partner in Mishmish Productions said archaeology was being sacrificed to development. ''Everything is pitched to developers.''
Sampling needed to be more comprehensive. Prehistoric sites of papakāinga and gardens could only be done by digging out the features to truly understand each site.
She said listening to the korero of hapu was essential to good archaeology because hapū were usually right if they saw something as important.
But once consent was granted for big earthworks, it could not be stopped, and telling the stories of the land was where a museum came in.
''Each of us have a responsibility to stop thinking about our own pocket and think about the wellbeing of future generations.
''It is giving people back their place in society and pride,'' Gallagher said.
