Susie Wolff said she had shown the speed needed to be taken seriously as a potential Formula 1 driver after her first proper test in a grand prix car.
The 30-year-old Scot spent a day's testing with her Williams team and just missed her personal target of breaking the one-minute-35-seconds barrier.
"It was a fantastic day. Overall I was happy," Wolff said.
"I wouldn't be doing this if I didn't think it was possible. It's about going out there and showing what I could do."
Wolff's fastest lap of one minute 35.093 seconds on Friday was 0.462 secs slower than Spaniard Daniel Juncadella, the European Formula Three champion, managed.
Juncadella set a faster lap - 1:34.098 - on the first day of the test on Wednesday. Williams race driver Pastor Maldonado clocked 1:34.116 on Thursday.
"I'd seen what he (Juncadella) had done (on Thursday) and the team were quite impressed by that and I was 0.4secs off that so it wasn't so bad," Wolff said.
She added that she had struggled to make the 'medium' compound tyre - the fastest available at the test - work effectively because of her limited experience.
"There was more potential there, definitely. But the team ran through the programme they wanted to so it was a successful day."
Asked about the prospects of her racing in F1 one day, Wolff said: "It was important for me to show I have the performance, it was important to show, given the limited laps I had, I can be on the pace.
"I was only 0.4 secs off the F3 European champion, the guy who's rated as an up-and-coming young star. For me that was important.
"If that has more meaning for other people because I am female, then I will use that to my advantage but I'm not going to play the card 'I'm a girl so give me the car I'm fast enough'.
"There were a lot of great performances from young drivers over the three days [of the test]. We're all fighting hard and I've got to continue to fight hard."
The test was mainly for teams to try out drivers of limited experience but race drivers were allowed to take part under strictly limited conditions to try out a new type of Pirelli tyre design aimed at preventing the multiple failures seen during last month's British Grand Prix.
The new tyres mate the construction used last year with the softer rubber compounds of 2013 and both Red Bull's Sebastian Vettel, who set the fastest time, and Ferrari's Felipe Massa said they had performed well.
"(There's) not that much of a difference," Vettel said. "We had three days, different drivers in all the different cars and no failure. That's good - in conditions that were probably worse than at the grand prix - even hotter, asphalt temperature was even higher.
"But no big surprise, we weren't allowed to rebalance the car and try different things but it was good to get a couple of laps and practise the feeling."
Massa added: "(On) the first lap (there) isn't a big difference but the consistency on the long run is a lot better than the race here in Silverstone and for safety it is better."