She is the youngest person to be called to the bar in 600 years and at just 18, Gabrielle Turnquest has already become used to questions about her age. By 12 she was ahead of her classmates. She started her first degree at the age of 14, graduating two years later on the day she also graduated from high school. "I guess it feels really good to have a law degree," she says, "rather than the age part of it."

Not many people knew how young Turnquest was at the University of Law, where she was studying with her 22-year-old sister. Most of the other students were in their mid-20s, although there were much older people too.

"I think once people figured it out, there was shock," she says, "I think that we had assumed that I was the youngest but there hadn't been any confirmation. Then it was all over with and we got back to studying."

Turnquest is the third of six children. Are they all high achievers? "We try to be," she says with a laugh. Their mother can take much of the credit for their academic success. A lawyer from Nassau in the Bahamas, she moved the family there from Florida when Turnquest was a child. Deciding the school system wasn't challenging enough for her bright kids, she spent several months researching curriculums from around the world, looking at which countries were doing best in which subjects and why.

Then she turned all that into her own educational plan, rented space in her office building, hired teachers and enrolled her children on to a programme she named Excelsior Academy. She even made a school uniform for them.

Turnquest insists there wasn't any pressure to excel. In fact, she says, because she wasn't comparing herself to her peers, she didn't really know what was expected of her. She just soaked up as much information as she could take, regardless of what age range it was aimed at. "My mother never gave us the impression that we were expected to complete everything," she says.

When Turnquest was 12, the family moved back to the US and the children went back to schools. By this time she was far ahead of her classmates.

When she got to high school the following year, she was able to take more advanced courses and she started a degree in psychology when she was 14. Turnquest's university classmates knew she was still a high-school student, though most assumed she was a senior (around 17).

When a mentor suggested she might not be taken seriously as a counsellor at such a young age, Turnquest thought about what to do next. Her sister had applied to study law in London and she thought this would be a good next step. "I guess the same could be said [about her age] for law, but it seemed as though there would be more opportunities to do behind-the-scenes work and the age thing would never come up."

Although she could have stayed in the UK and become a barrister, she now plans to work as a lawyer in the fashion industry – she starts an apparel industry management course in the autumn, while studying for the multistate bar exams.

So, does she ever feel that she has missed out on anything, that she has moved too fast? "I guess I missed out on going to university with the people I knew before, but I've met a great group of people going to university the way I did. I now have this time to figure out what I'm going to do next and I already have a degree, so I have more opportunities open to me. I honestly don't think I've missed out. I don't think there was anything I could have done at 15 or 16 that I can't do now – just with a law degree."

• This article was amended on 13 August 2013. The original version referred to the College of Law. This should have been the University of Law and has now been corrected.