The triumphs and travails of Mary Kom's extraordinary life, from the paddy fields of Manipur to five-times world boxing champion and Olympic bronze medallist, include scenes of murder, heartbreak, racism and redemption. It sounds like a film. Soon it will be, with Kom played by the Bollywood star and former Miss World Priyanka Chopra. The biggest challenge will be squeezing everything in.

Not that the 30-year-old Kom is hanging up her gloves. Fresh and alert despite a flying trip to London from India – 25 hours, in and out, with an eight-month-old baby – she announces that she is about to start training for Rio 2016, while also trying to do more to improve women's lives in her homeland.

Since 2006 she has run the MC Mary Kom Boxing Academy, which gives nearly 40 disadvantaged Manipuri children structure, education and order. Now, with Vodafone's support, she is setting up women-only self-defence camps and an SMS service to provide safety tips for women across India. "Women are scared to walk in public on their own in India," she claims. "And after what happened [with the gang rape] in Delhi, more women are wanting to box and do self-defence."

Kom is delighted to be back in east London, a light jog from the ExCeL Arena, where one life ended and another began. She was a five-times world champion in the 46kg pinweight class but her successes had been largely ignored. Then came bronze in London in the 51kg flyweight class, the lightest weight for women boxers at the Games, and – at once – the spotlight, fame and money, all hurtled her way.

"London was where all my dreams came true," she says. "Before then I was a five-times world champion and a nobody. I wasn't happy. I wanted more. Everyone watches the Olympics, so when I got a bronze medal doors opened, things changed, and people in India started recognising me."

Even so, after losing to Great Britain's Nicola Adams in a close semi-final she felt compelled to apologise to her country. Wasn't bronze enough for them? She laughs. "They expected me to win a gold! Most of them didn't know that I'd only fought in two competitions at 51kg. But sometimes when we lose, it is good for us. I will be back for Rio. As a sportsperson, if you are not planning to win the next competition, you might as well stop."

Kom's autobiography, published last December, is called Unbreakable. It is an apt title. In more than a dozen years, she has never felt the canvas pulled from under her boots like a carpet in a magic trick. She had twins and a year later won another world title. And, from lowly beginnings, she has flitted past whatever boulders have been placed in her way.

She grew up in Manipur, in India's north-east, a state that barely caught a whiff of India's economic boom. Kom's parents were among the poorest of the poor: her house "more like a hut", her bedroom, which she shared with her two sisters and brother, "more like a box". There was little meat or fish – too expensive – or paddy field to grow rice. They worked the land but did not own any of it. When Kom told her father she wanted to be a serious boxer he sold his prized possession, the family cow, for £175 to pay for travel and training costs.

Before then Kom had boxed in secret. Having moved away from home in her mid-teens to train as an athlete, she turned up at a boxing gym in torn tracksuit, eager to try a new sport, having seen that a Manipuri boxer called Dingko Singh had won gold at the Asian Games.

"I was really scared because I didn't think my parents would let me continue," says Kom. "I also worried that if I got an injury, I wouldn't be able to help my family." Her father found out when he saw her picture in the paper after she won the state championships. Afterwards he feared that if Kom lost her looks she might never marry. But Kom was too quick and clever to get hit regularly. And marry she did.

But in 2006, shortly after her third world title, her father-in-law – a local chief – was taken away from his house and shot in the head. "It was very hard," she says. A long pause; sentences started then halted. "You know about Manipur, it's a violent place." A whisper. "This was planned … I suspect it was our community, our own society. People were jealous of us. They don't want me to succeed. They thought if I had a family problem I would not come back to fight. My husband wanted to take revenge but soon afterwards we found out I would be having twins, so he knew he had to take care of me and our children. So instead we prayed to God together, to hope everything would be better."

There were eyewitnesses but no one has ever stood trial. Kom ploughed on, despite occasional racism – Manipur is close to the border with Burma and she looks more light-skinned than most Indians – through the congenital heart problem in the younger of her twins, and the double demands of boxing and motherhood.

"Being a mother is very difficult for me," says Kom. "Especially when I am training. I can't be with my children because they disturb me. They want attention, they want their mother. But only when I am away from them can I train properly. And that's so hard."