Mr Tuliau has bought a house and he, his children and parents will move out next week, leaving their current accommodation to the Malaitais, who will need to furnish it themselves.
They are hoping to buy a bed for Sienna after she returns from a 10-day chemotherapy treatment at Starship Hospital in Auckland.
However, before the family divides, there are 15 mouths to feed each day and just a slim portion of money available for food.
Ms Malaitai calculated 88 per cent of the family's budget went towards bills such as power, phone, rent, doctor's visits and petrol, with the remainder to spend on food.
"Petrol's a big thing for us because we both work."
However, the Malaitais and Mr Tuliau ensured the household's 10 children never went hungry.
"It's difficult, but we manage to feed the kids. I'll sacrifice any bill to make sure we have food in the home."
Ms Malaitai had noticed the bare necessities were more expensive in supermarkets, particularly bread and milk.
"The sad thing is it's the basics that are getting more expensive."
The price of bread had risen and there were fewer slices of bread included in packaging.
"Meat is the hardest thing," Mr Malaitai said.
"It's so expensive, so we try and get it when it's on special."
Ms Malaitai has also found creative ways of preparing 10 school lunches a day.
"The kids have never gone to school without food ... I can feed my children $20 worth of lunches a week."
Five loaves of bread lasted the week, with one loaf going into sandwiches for school lunches per day.
Popcorn was also a good lunchbox filler, at about $1 a bag and the kids went through two bags a day, Ms Malaitai said.
She also kept the family full with home baking; keeping the pantry stocked with flour, sugar and oil and buying eggs from a local egg farm for as low as $3 a tray.
For dinner, the family adheres to a meal plan and favours staples such as potatoes, rice and pasta with mince sauce, stocking up on supplies when possible.
Takeaways are rare and "a real luxury".
They spend $20 to $30 on dinner per night and share the cost with Mr Tuliau.
The family's motto is "food tastes better on a well-set table," and the children never complain, Ms Malaitai said: "We may be struggling but I'll never teach them they're poor, because there are people worse off than us."