She intends to get in that bit of extra training - Hannah is heading to Argentina next month with the NZ Under-17 team and is likely to be named in the Under-17 World Cup squad later in the year. She also hopes the facility helps give her school's first XI the edge.
It's a team she describes as having a lot of potential.
"We're not a bad team, we're strong on the Shore but when we cross the bridge ..."
Cityside it's Mt Albert Grammar that takes some beating. But Carlsen notes the Westlake girls could have an advantage this season.
"Trainings will never be cancelled!" she says.
She says the only difference she's noticed on the artificial surface is that it's softer and the ball rolls faster. That's because of the shock pads beneath the surface, explains school property manager Grant Brown.
"The school did its research before laying the field and learned that adding the rubber padding helped prevent injuries," he says.
The speed of the surface comes from the dual monofilament turf - a high-quality mix of straight and curly fibres. The football fields are two-star Fifa-rated, the highest rating available.
Already, the school has attracted athletes wanting to try outthe playing areas. While we're there, another ball flies across the impressive "London blue" hockey pitch, water spraying as the hard, white projectile skims the turf, driven by the stick of one of the Black Sticks women practising.
The director of sport at Westlake, Dean Flyger, says the the hockey turf and warm-up field, three outdoor tennis courts, three outdoor netball courts, two cricket nets, an artificial wicket - cleverly slotted between the two soccer fields - are well worth the wait.
"2011 was tough, a whole year without facilities, but the hockey girls were playing on it at the end of the year and it's fantastic now," he says.
Having an all-weather hockey turf, under lights, is also good for women's sport beyond the school.
"It's allowed us to set up a partnership between Westlake Girls' and NZ Hockey that's really beneficial to both parties. The Black Sticks women can use our facility for training and, in turn, our girls get exposure to the best players in the country," says Mr Flyger. "They watch how they train, and it's fantastic for them."
The fields are fully irrigated and collect water from the catchment area into 100,000-litre tanks. That water is used on the hockey pitch to make the ball skim - it can be watered with 83,000 litres of water in 12 minutes.
By June the largest artificial turf development in Australasia will also feature indoor venues. Construction has begun on four indoor netball and six tennis courts, which will be covered in a Cloud-like structure like that on Queens Wharf.
All up, the whole complex will cost $7.5m, money from the sale of two of the school's playing fields to the former North Shore City Council. Another $50,000 from a trust has been used for lighting.
Westlake deputy principal Paul Davis says the school has enough money left to fund maintenance of the facilities for two years. In that time the board will work out how to ensure turfs can be replaced when due in about 12 years.
"Part of that funding will come from hiring out the facilities to the community, including international sports sides," Mr Davis explains.
Already, the Korean and Japanese hockey teams have requested their use, because it's the same playing surface the London Olympics will use. Mr Flyger says that's good for our hockey coaches, who can see how other teams train.
Ground staff won't have to mow and rake fields anymore, saving money. "We have our handmower on Trade Me now," Mr Brown jokes.
To offset the artificial areas, a number of natural green areas are being made within the school, but there have been no complaints about a lack of real grass.
"All girls can use the fields, they can't eat on them but they can run around like normal," says Mr Davis.
"And when it all comes together we will have a huge facility, the best."
HOW THEY GOT IT
The Westlake Girls' artificial sportsfields are the result of 15 years of negotiation by the school with the Northern Busway, Ministry of Education and the old North Shore City Council.
The school lost two of its grass playing fields to the development of the busway. The new fields took a year to build and were officially opened in November, but this will be the first school year all facilities will be available.