"You might be facing the worst challenge you've ever faced and it might feel all doom and gloom but don't give up."
Her "interesting childhood" included moving a lot as Don chased business opportunities, but the whole family always pitched in with ideas and strategies to work through problems.
Many of the issues back then are still top of mind as Frog Parking shoots for its goal of becoming a $100 million company within five years, particularly managing the financials.
"When I was a kid, and today that's still one of the biggest challenges, is working capital and managing cashflow and changing up what you did last year.
"You don't want to do the same thing this year, you've got to change your strategy, you've got to beat the doors down, push the envelope, never give up."
To continue the drive into overseas markets - 90 per cent of Frog Parking's sales are international, with Disney, Nasa and the City of Beverly Hills among its repeat customers - a bigger war chest is needed.
The company is in the process of preparing for a capital raising, the details of which are still under wraps, with the money earmarked for growing the sales and support functions.
It has brought Franceska Banga, former chief executive of the NZ Venture Investment Fund, on board as a director to help guide it towards its growth goals.
Banga brings a completely different view, based on her experience with venture capital, which is "very, very valuable", says Sandbrook.
"Our board meetings used to be: Dad and I would go for a cocktail up at the local restaurant at lunchtime and talk about what we are going to do next or what's the strategy for the next weeks.
You might be facing the worst challenge you've ever faced and it might feel all doom and gloom but don't give up.
"Now we have a proper structure, we have board reports and we're managing it as if we are growing it to a $100 million company," she says.
"When you're a father and daughter and he's the entrepreneur and I'm the implementer of the start-up, you can get carried away in your own world and it's always good to have a third party that can check for you. We really wanted to get serious about growing this company into a beast, so we thought let's go and find the best person that we can to be on the board and help in that advisory position."
One of three children, Sandbrook has been the only one to team up with her father in business.
"I've always been pretty business focused," she says.
"I have an extraordinary view of myself in the future and I know that I have some pretty strong goals and I know that being in business myself is the only way that I'm going to achieve that because that's me being in control of my own destiny."
She backed herself to do an MBA in her 20s, reapplying after she was knocked back the first time for being too young.
When you're a father and daughter and he's the entrepreneur and I'm the implementer of the start-up, you can get carried away in your own world and it's always good to have a third party that can check for you.
With so much of the business growth coming from overseas, it means Sandbrook is out of the country for a third of her time.
That's one of the disadvantage of continuing to base the firm in Palmerston North. Frequent international travel means an additional leg from Palmerston North through to Auckland.
It can also be harder to attract key staff at senior levels, she says, although the company's growing reputation and graduates from Massey University are helping to fill the gaps.
And, she says, the city offers a great lifestyle.
Sandbrook, who trains Clydesdale horses in dressage in her down time, says her primary school-aged girls go to school near the company's offices and head there at the end of the school day.
Life at a high growth firm is not going to suit everybody, she admits. "It's high stress.
"You can be doing on thing one day, next day you're doing another thing so you've got to have flexibility.
"You've got to want that high stress environment, so it's not for everyone but there are lots of people now who are young, upcoming tech people want to make it in New Zealand and they think that by aligning themselves with a high growth company they can achieve something great."
