Novelist Kia Abdullah would like us all to be kinder to each other. When people make assumptions about her based on her cultural background (she is second-generation Bangladeshi), Abdullah prefers to “make a gentle correction – you don’t need to hit someone over the head with it”.

While others might get hot under the collar, she handles cultural misunderstandings with grace – and thinks more people should do the same.

“In day-to-day interactions we should approach one another from a place of kindness and forgiveness,” insists Abdullah, 40, whose latest courtroom drama, Those People Next Door, is out now. “You can’t live your whole life angry. I don’t want to live like that,” she continues.

But plenty do, as the reaction to the questions asked of charity boss Ngozi Fulani by the late Queen’s lady-in-waiting Lady Susan Hussey in November demonstrated. At a reception at Buckingham Palace, Fulani – who was wearing African clothing – was asked repeatedly by Lady Susan where she was “really” from. To Fulani, it was an example of “institutional racism”.

Others felt Lady Susan, who apologised and resigned, was hung out to dry for genuine curiosity.

“If you ask where someone is from originally, once, that’s fine – I’m often curious myself about where people are from – but then you accept their answer,” says Kia, who was brought up as a Muslim in east London. Indeed, she believes everyone is capable of cultural “clumsiness”.

“It’s a minefield, and I worry about putting a foot wrong myself,” she says. “I’m never setting out to be hurtful, but sometimes I’m clumsy.

“A black solicitor friend was telling me people often assume because she is black she is working class. I realised I’ve sometimes made that assumption about others. Some would say it was an example of racism. I’d call it ignorance.”

All this from a woman who has frequently been on the receiving end of other people’s presumptions. Known for her gripping courtroom drama novels, Abdullah was on a cruise ship a few years ago when an older American couple asked where the steak restaurant was.

“When I said I didn’t know, they asked me what other restaurants were on this floor. They assumed I was a member of staff – probably because I was Asian like most of the crew on the ship.”

After explaining she was a fellow passenger, the couple looked “mortified”. Fortunately, they parted company on good terms.

“I expect someone from the younger generation would have taken a hard-line, zero-tolerance approach to such an error,” she adds. “There are merits to both choices, but I tend to err on the side of forgiveness. As long as the person learns from the faux pas, let’s all be kinder and a bit more understanding. Sometimes by being unforgiving, we are making life harder for ourselves.”

Another time, at a literary festival where she was giving a talk, Abdullah asked for the location of the authors’ green room – the backstage area. “I was asked, ‘Are you a volunteer?’. Was it because of the colour of her skin, or was it a perfectly reasonable enquiry?”

The truth is we don’t always know. “It’s not always black and white,” Abdullah explains.

It was such nuances she wanted to tackle in her new novel, the story of the Khatun family and their desire to make a better life.

They face challenges after their next-door neighbour knocks over a Black Lives Matter banner in their front garden. This “snowballs into catastrophe” – leaving everyone questioning their prejudices.

“My character Salma’s instinct is to take [the sign] inside and maintain a good relationship. But sometimes, you’ve got to stand up for yourself and the people you love.”

The incident was partly inspired by a former next-door neighbour who would place their dustbins in front of her garden instead of theirs. “I didn’t even have the boldness to just push the bin back,” she says. “It’s a situation ripe for conflict and drama – how can you know for sure that tension between neighbours is racial?”

Abdullah thinks crime fiction is a powerful vehicle for social commentary. “It can engage in weighty issues like these, but in the guise of a highly-accessible thriller.”

The author believes she inherited her tolerance from her parents, who were Bangladeshi immigrants. “My parents were really grateful to be here, so I expect some of that attitude has rubbed off on me,” she says. She grew up on free school meals, one of eight children in a working-class home in Tower Hamlets, east London. Her first marriage, in her 20s, was arranged. Now she is married to her second husband, who is white.

“My niece has also married a white guy. She recently had a big Asian wedding. It was so heart-warming because we all decided to wear Western dress, and her husband’s family were all planning to wear Asian dress. It was a beautiful moment of cultural exchange.”

As a child, Abdullah was considered something of an anomaly by her parents. “I basically refused to eat unless my mother told me a story,” she recalls. However, her parents didn’t read or write English, so there were no books at home, other than ones she brought home from the library.

“I was seen as the wayward child, fuelled by the fact I was a voracious reader,” she explains.

Heavily influenced by the 1908 novel Anne of Green Gables, by Canadian author Lucy Maud Montgomery, she “saw how the character subverted the expectations placed on her, and I realised I didn’t have to be quiet and good: I could set my own course in life.

“I saw education as the way out of poverty and said: ‘I’m going to university’.” Abdullah graduated with a first-class degree in computer science and has since helped “shepherd” her nieces and nephews into good careers. “One is a nurse, another a programmer,” she says. “The great thing about Britain is progression is inevitable.”

Abdullah has sold more than 70,000 copies of her first three novels, which have dealt with issues such as homophobia, tribalism and racial tension. She refers to their delivery as the “Trojan horse” – the insight around which the story is wrapped. “It’s not sermonising or moralising,” she insists. “Your job as a novelist, first and foremost, is to entertain.”

To encourage other working-class children, she mentors students in Tower Hamlets, one of London’s poorest boroughs. “I see so much promise and potential there,” she says. And her social conscience permeates her electrifying writing, too.

“I’m trying to get people to engage. But I know that I only have true freedom when I can write positive as well as negative stories about my Muslim community.”

• Those People Next Door by Kia Abdullah (HarperCollins, £14.99) is out now. To order for £13.49 visit expressbookshop.com or call 020 3176 3832. Free UK postage and packaging on orders over £20.