"I was never going to go straight into it so I did a Masters then worked in the city first in insurance broking then management consultancy. I did it for two years then there were some changes at the forecourt business. My parents had an operations manager who had been working for them for years," Susie explains. "He'd always been into computers and did computer work in his spare time but during the dotcom era, he left to concentrate on that. And it was his leaving that prompted me to come back."
Susie describes her move as "coming back" because she was no stranger to the business. All through school and university she'd worked there in the holidays. "I did have a handover period with the operations manager where he basically taught me everything about accounts and the ops side of the business in three months. I've still got the notes and every year-end I go back to them."
Susie was keen not to be seen as the "boss's daughter" even though she clearly was. "Most of the managers knew me already from my holiday work but I made it my goal to learn everything about the business. And although I came in at operations manager level, I still did shifts in the shops."
It's a similar story for Rob Exelby, son of Exelby Services' boss Mike. When the boss's children join the family firm there's always potential for resentment from existing members of staff, but Rob says that's never been a problem for him.
"There might have been a problem had it not been the case that I'd previously worked at the company. Between the ages of 14-16 I worked in the head office helping accounts with the paper work and then, when I finished university, I worked for a time on the tills at one of our BP sites on the A19. I think that experience and getting to know the staff put me in good stead."
And, like Susie, Rob worked externally before joining the family firm on a full-time basis. "Dad gave me the option to join as soon as I'd left school but I enjoyed the technical stuff and so decided I wanted to do engineering. I graduated as a mechanical engineer then worked at an engineering firm for three years."
He says this time taught him life skills, business skills and negotiating skills.
"I was responsible for engineering projects, sourcing finance for those projects, and that gave me an idea of value for money which has come in very handy when sorting out fuel supply deals," he explains.
"I'd advise anyone joining a family business to go off and do a different job first. Work for a different boss, get some new skills personally I found that invaluable."
Susie says her time spent working elsewhere first gave her the self-belief that she could do the job. "It gave me the confidence not to question myself too much. I learnt other bits of knowledge and gained experience too," she says.
Today Susie runs the business operationally. "But my dad is still very involved," she says. "He's really into strategy and development; he loves building and having plans.
"Sometimes in a family business there is a controlling figure but with Dad he's very happy to let me do what I want, with his guidance. He's my biggest inspiration and I always go to him first with things."
It would seem that having a good relationship is key for a family that works together. Rob says he has a very easy-going relationship with his Dad: "At one point we shared an office for a few months and that was fine. Dad is very good, if I have any ideas he usually lets me get on with them. He gives me guidance but he gives me the freedom to explore new things too.
"We've a natural business working relationship and we manage to keep business and home life separate. Dad is very pleased that I'm involved in the business. It means that if he wants to take more of a back seat in a few years, he'll be able to."
Shane Thakrar has been with family firm HKS for seven years now. His father Sailesh runs the company with his brothers. but Shane's involvement means he's been able to take on a lot more of the day-to-day stuff so his father and uncles have more free time.
But like Susie and Rob, Shane worked elsewhere first he did a year in corporate finance prior to joining HKS and says it was good to get that experience and then be able to share that knowledge and new ideas with the family company.
His tips for anyone joining a family firm are to firstly make sure you understand the business. "You also need to be open minded and remember that different people have different views and also different management styles."
Mike Cheskin has two Gulf branded sites in Gloucestershire and two of his three children work in the business. His daughter Ruth went straight into the business. She went off to university but decided it wasn't for her, so she came back and her Dad offered her a job.
"I had no hesitation in accepting," she says. "Dad had worked in petrol stations all my life so I was familiar with them. I used to help out in the shop at the weekend so I knew the shop side well."
While Ruth looks after the shops, her brother Matthew looks after the fuel and the accounts. Mike says he's no longer driven by making money as he has sufficient for his needs so he's quite happy for Ruth to try new things, even if there's a small risk that the business could lose a bit of money as a result. "But Ruth has a very good track record," he says. "To be honest, she has spent money on things I wouldn't have bothered about. Occasionally I've pulled in the reins but not too often. If she does make a mistake it won't be a massive one; the business won't crumble."
One of Ruth's great successes has been the addition of Tchibo coffee: "Dad didn't think it would work as we're not coffee drinkers. He didn't realise how popular it would be," she explains, describing hers as a "blessed situation" because it's not just all about the money.
Mike says he's very pleased his children are involved in the business but adds that they were definitely not forced into it. "I can never see myself retiring but I have retired from various responsibilities and the service stations run perfectly well without me," he adds.
"My one bit of advice is forward planning as you never know what's around the corner. Planning for things like taxation rules on inheritance is vital as it's unfair to burden your family with such things."
Ruth's advice is to not take things too personally in business. "Dad is a blunt person he's blunt with the staff and with us it's not personal, it's just the way he is, he speaks his mind."
But they get on really well they live next door to each other and even go on holidays together. "We do talk about the business away from work but usually about something funny that's happened earlier that day," she says.
And for the future, it looks like there could be another generation following in Ruth and Matthew's footsteps as Ruth says her nephew, who is just six, already finds the petrol stations fascinating, so you never know.
Tips for succession success
Plan ahead. Don't leave it too late experts say you should start thinking about who will take over 10 years before you expect to retire.
If you have children, you can't just expect them to want to join the family firm.
If your children are coming into the business think about them having a few years' experience elsewhere first you never know how valuable that experience could be for your business.
If children taking over is not an option, you may want to look inside the business so make sure you know your staff and their ambitions. Remember that not all 'deputies' want to be top dog; many prefer being second-in-command.
Ask your friends and peers how they have planned for the future.
If your succession path is not clear, think about getting external, expert advice.