From the age of 14, she has run her own business, determined to carve out a future for herself in motorsport, but never expected to end up in F1 Academy in her twenties. And yet she seized the opportunity with both hands, making the most of it with a breakthrough wildcard appearance at Zandvoort in 2025. In the run-up to her first home race as a full-time F1 Academy driver, we caught up with the Dutch driver at Jack’s Casino Racing Day in Assen. She is attending this major Dutch motorsport event alongside her MP Motorsport team-mate, Nina Gademan, for a series of autograph sessions with the stars.

Kosterman finds herself halfway into her first F1 Acadamy season with the support of world-renowned toy manufacturer LEGO, but a few years ago, when she was given the opportunity to move up from karting into motor racing, initially in the Fiesta Sprint Cup Benelux, this future was still far from her mind. Single-seaters were a distant dream, but it took this dream to get it all started – by first turning a wheel at the Kartfabrique, an indoor kart track in the Dutch city of Utrecht. “Actually, it was my dad and my brother who started out, because I was doing dance classes with my mum. But I got jealous of my dad and brother because they went to the Kartfabrique every weekend. I wanted to do that too! My mum thought it was all rather scary, but I was also doing football and judo. So I was actually involved in a couple of tough sports already. Eventually, I was allowed to take part in one session at the Kartfabrique. Since then, I’ve never stopped, and it’s always remained my dream to become a racing driver.”

So now there were two young Kostermans that got into go-karting. It soon turned into competition karting on the outdoor tracks across the Netherlands: an expensive pursuit, so arrangements had to be made at home. “Our parents told us: ‘We have no silver spoon, so your brother gets to do four years, and then you get four years. And that’s it.’ But I’m in my ninth year now!” There’s a perfectly fine explanation for that, however, as Kosterman decided to become financially independent from the age of 14. “I set up my own business – still in my mum’s name until I was 18 – because I really wanted to get into motor racing. That was because, in 2019, I took part in the final of FIA Girls on Track – Rising Stars, the FIA programme for young female karting drivers. I made it into the final five and was given a drive in a Formula 4 car. On my return in the Netherlands, I got talking with the KNAF, the Dutch federation, as I was now part of their KNAF Talent First talent programme. Eventually, I did receive an offer to race in Formula 4, but it proved simply too expensive for a 14-year-old girl. Another offer was for the Fiesta Sprint Cup Benelux. Through my own company, I started my search for partners, and that’s how I ended up in motor racing. I’d never have got this far without my partners, so I’m glad they’re still with me. Some of them have been supporting me for eight years.”

Kosterman tells us about it with obvious passion and joy. Her approach is similar to that of Richard Verschoor, who also secures his own funding and plans his own career. “It’s now simply my whole life. I’ve always stayed true to myself and have always spoken openly about my dream. That’s what you need to win over partners. People only see the racing, but that’s just 10 per cent of the work. The other 90 per cent is in finding the budget, in creating content and collaborating with partners. My family are still there for me: my mum does the bookkeeping, my dad always comes up with the best ideas. My brother has stopped racing because he’s gone off to university. He’s more into partying, and that doesn’t really go hand in hand with motorsport! People sometimes ask: don’t you think it’s a shame that, as a young girl, you have to miss out on all that? My answer is always: no, of course not! This is my dream, I want to be here. And I’m really enjoying life in the meantime.”When she started in the Fiesta Sprint Cup, she no longer had single-seaters as her goal. “I’m 21 now and in F1 Academy I’m racing against 16 and 17-year-old girls. So I’d actually put it out of my mind – until F1 Academy was announced. My first thought was, this is my golden opportunity! From that moment on, I knew what I wanted to work towards.” It all started with a lucky coincidence – a one-off appearance in Indian Formula 4, standing in for a driver who had broken his wrist. “I was offered the drive for free. That was my first experience with MP Motorsport, as they were providing the technical support in India. That’s how I got to know Wouter Blokhuis, who was responsible for setting up the programme there. And now he’s my team boss again! Yes, there are two major teams in the Netherlands, but MP has always been my dream team.”Before she got her F1 Academy break, she took in eight races in British F4, all to prove herself and qualify for the wildcard appearance at Zandvoort that would turn out to be her breakthrough. How did she experience that first F1 Academy weekend at Zandvoort? “Chaotic!” she says honestly. “You find yourself in a world you’re not used to. What do all these people want from me? Why would they want to have their photo taken with me? The racing conditions were different too, because Formula 1 was racing there. There was so much more grip, calling for a completely different driving style. My experience in the Fiesta was actually of no use to me, and I barely had time to get used to it, because it’s a championship that requires a lot of media appearances.” It only sank in afterwards, she explains. “We’re still talking about it with the family. On Sunday we were done, and I had one more media appearance, at the Ziggo Race Café in a beach club by the sea. Afterwards, we had dinner and watched the sun go down. We all looked at each other and then burst into tears at the same time. I’ve only ever seen my father cry once in my life – and that was right there. It was the most beautiful moment of the whole weekend.”It came after three intense days in which she lined up ninth on the grid twice – in a field of 18 cars – and finished seventh in the second race. It was a debut that made an impact. “I didn’t have time to think, it all just flowed. It was a shame about the first race: a small mistake with the tyre pressure meant that I had to start from the pit lane. But I didn’t come here for the points finishes, I just wanted to prove myself. And I could equally do that by staging a comeback from the back of the field, moving up from last to 12th. And then, in race 2, I was able to show that I can hold my own at the front. Looking back, these were actually the ideal conditions.”

As a result, she was offered do a full F1 Academy season in 2026. And not just any season: it came with the support of legendary toy manufacturer LEGO, for whom she is now an official ambassador, and with her ‘dream team’ too, MP Motorsport. “I’m really happy about that. Through their ITQ Performance Programme, they’re helping me with a physiotherapist, a dietitian and a mental coach. I’m a proper Dutch girl, so I thought, I don’t need a coach like that. Well, I do! The simulator sessions we’re getting with Atze Kerkhof at Verstappen Pro Simulation in Tilburg are brilliant too. I’ve never sat in such a good sim before. It’s so realistic that you can really take the experience with you onto the track. In particlar, I’ve been able to fine-tune my braking technique, as that’s done very differently in an F4 compared to trail braking a front-wheel-drive Fiesta.”

Since that first weekend in Shanghai, Kosterman has seen her feel for the car improve by leaps and bounds. “I’m only just starting to really understand the car. I’m not quite where I’d hoped to be, but you can see the upward trend. In this sport, it’s 20 per cent success and 80 per cent disappointment, so it’s hard work. But I’m grateful that the team is giving me the time to get there.”

Now her home race is just around the corner, no longer as a wildcard driver but as a full-season F1 Academy driver. How important is having the home advantage to Kosterman? “Very important. I need the support of the home crowd. I went to Shanghai without my dad because he couldn’t get time off work. But after Shanghai – which was quite a tough weekend – I told him: I really need you. The whole Dutch atmosphere at the event plays a part too. I still remember last year, driving down the straight and seeing all those orange-clad supporters in the grandstands. That was truly a confidence boost!” She also believes that her track knowledge adds to her home advantage. “It would be ideal for me if it started to rain. Lots of the girls don’t have any experience driving in the rain at Zandvoort, and I know exactly which lines are fast in the rain. Although we did have a two-day test at Zandvoort recently. It would have been better still if nobody had tested here…”

Kosterman is only halfway through her first season in the F1 Academy, so we ask her if she has a plan B. “I haven’t actually thought about that yet. Of course I want to stay involved in motorsport, but the question is whether I’ll be able to keep doing so at this top level. Having to raise the budget yourself every year is quite stressful. I agree that a move into sportscars might be an option, but that’s just as expensive. You’d still need sponsors – and my current sponsors would have to be willing to make that switch with me. And yet… even if I can’t continue as a driver, I want to stay involved in motorsport. For example, as a data engineer, because I absolutely love puzzling over the data. That’s when the nerd in me comes out! And I’ve been coaching children in karting for years. I really enjoyed doing that, so who knows…”