"We were hoping it would be this successful, we've kept our fingers crossed that people would really embrace this film and so far they seem to be," van Beek said.
While the film fills its brief as a comedy, van Beek said there were several more serious aspects that she and Sami aspired to.
"That was to put some strong female characters up on screen and to have some strong female creatives behind the camera as well," she said.
"We feel really proud, because even though we're delivering this quite silly, fun-filled comedy, we're so pleased that it has such a diverse great cast and all of those women up on screen as well."
The Breaker Upperers has barely started its run in cinemas here and overseas but Van Beek said she and Sami were already coming up with ideas for a new film to do together.
"Madeleine keeps talking about a trilogy - that we're going to create three buddy films, she might be joking, I can never tell."She's so busy I can barely get her on the phone. She's probably too busy to do this interview, she was probably offered this interview first then didn't pick up the phone so they rang me," van Beek joked.
"That's what happens with us, Madeleine was cast in a small part for Hunt for the Wilderpeople and couldn't do it, so I got called. I got up at five in the morning, went and did my scene and I was terrible - Taika cut the scene."
Fellow Kiwi Niki Caro, who wrote and directed Whale Rider, was thrilled to see The Breaker Upperers climbing the New Zealand box office ladder.
"It's clear that Kiwi audiences are responding as enthusiastically as the Americans to their refreshing female-driven humour," she said.
She said she was looking forward to having them join her as the next two female directors to make it to the Top 10 grossing films at the NZ box office.
The two-week mark
1. Hunt for the Wilderpeople - $3.6m
2. Boy - $2.1m
3. World's Fastest Indian - $1.7m
4. Once Were Warriors - *
5. Whale Rider - $1.57m
6. Sione's Wedding - $1.48m
7. What Becomes of the Broken Hearted – *
8. What We Do in the Shadows - $1.309m
9. Footrot Flats – *
10. The Breaker Upperers - $1.08m
*Too far back for two-week mark data but placing based on overall grossing figures.