Sarah Olney: ‘I’ve been elected on a clear anti-Brexit mandate and I’ll be fighting to maintain close links to the EU.’ Photograph: Carl Court/Getty Images

Sarah Olney, the new MP for Richmond Park and north Kingston, only joined the Liberal Democrats last May after its crushing defeat in the general election that handed the Conservatives an unexpected majority.

Before that, the 39-year-old accountant, who lived in a semi-detached house in north Kingston with her husband and two children, had voted Lib Dem but never been a member of any political party.

“It never occurred to me [to join one],” she said. “I didn’t grow up in a political family. I don’t have political friends. It wasn’t on my radar at all.”

Her suburban middle-class background has little in common with Zac Goldsmith and the rest of the Goldsmith family, who were less than gracious in defeat. Goldsmith’s brother Ben said “even by Liberal Democrat standards, Sarah Olney is unimaginably drab” in a tweet in the early hours that was hastily deleted. In a rewritten version, he called her “utterly dreary” instead. In response, however, Olney would only say she was not prepared to get personal.

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Lib Dem Sarah Olney beats Zac Goldsmith to win Richmond Park byelection

Olney grew up in Surrey Heath. Her father was a headteacher and her mother a nurse. “They voted Tories, they are Tories,” she said of her public-sector parents.

Would they still back Theresa May’s party now?

“I don’t know, I expect so. The last time they had an opportunity to vote I wasn’t a Lib Dem,” she said, before adding with a laugh that she thought her mother would back her new party in the future.

Not that her parents are fans of their local MP, the arch-Brexiteer Michael Gove. “They hate him, they can’t stand him, he’s very unpopular in the constituency” she said, arguing that it was his desire to pursue “radical change in education” that put off some voters.

“He wanted to shake things up, but you vote Tory for stability, for security, for competence. You don’t vote Tory for radical change,” she said.

Olney lives with her husband, Ben, a town planner, and their two children, Isabel, seven, and Rufus, three. She said her daughter was “very proud and very excited” about her new role, although she was too young for it to seem unusual. “Its just ‘that’s what my mum does’.”

Olney said she saw herself as a non-partisan person who was ready to work across the political aisle, and who wanted to focus on her three priorities: Brexit, Heathrow and the NHS.

Was feminism a big driver behind what she wanted to achieve? “I think there are certain issues that affect women more than men, things like domestic violence, equal representation in parliament, equal pay, we are still not there,” she said. “I would want to make common cause with other MPs who want to make changes in those areas.”

She said her experiences of getting appropriate training and qualifications to secure a job – she was an accountant at the National Physical Laboratory in Bushy Park – that paid enough to cover the mortgage and fund childcare were an important part of her motivation.

She admits she is no expert when it comes to the workings of the House of Commons. “I’ve got a lot to learn about parliamentary process,” she said. “I wasn’t planning to become an MP. I haven’t studied the text books yet so I need to familiarise myself with the process.

“But I’ve been elected on a very clear anti-Brexit mandate and I’ll be fighting hard for Britain to maintain close links to the European Union.”