Just two months ago, two-time Oscar winner Sharmeen Obaid-Chinoy proved that a film really can change the world when Pakistan Prime Minister Nawaz Sharif declared he would change the law affecting honour killings. But for the celebrated filmmaker, journalist and activist, it has not been without personal risk.

Making acclaimed documentaries on such contentious subjects as honour killings and acid attacks on women has brought death threats that are not easily shrugged off in a country where a Taliban gunman shot teenager Malala Yousafzai, the Nobel laureate, for advocating for education for girls.

"It's not an easy job, especially in a country like Pakistan where there is deep-seated misogyny," Obaid-Chinoy says from New York, where she is on a speaking tour. "Any prominent woman, not just me, who takes up these causes is harangued online and now with social media receives death threats.

"In the city that I live in three prominent women were shot dead outside their home and their workplace. It was done in a manner to systematically silence them and none of their murderers have been found."

A series of confronting documentaries have given the 37-year-old from Karachi a stunning list of accolades that include five Emmys, a Crystal award from the World Economic Forum in Davos and being named one of the 100 most influential people in the world by Time magazine after she became the first Pakistani to win an Oscar four years ago.

Her 2010 TED talk Inside A School For Suicide Bombers has been watched more than a million times online.

Obaid-Chinoy started out producing then moved into directing documentaries focusing on marginalised communities, refugees and women from countries such as Afghanistan, Iraq, Syria, South Africa, the Philippines, Saudi Arabia and East Timor as well as Pakistan.

To give role models to young Pakistanis, including her own two children aged five and one, she has moved into fiction filmmaking with her country's first computer-animated feature film, 3 Bahadur, about three 11-year-olds with super powers. It was so successful last year that she is now making a sequel.

Obaid-Chinoy won the Oscars with two powerful short documentaries about attacks on women in Pakistan.

The first was 2012's Saving Face, about two of the 150 women who are attacked with acid ever year, often by men who have been rejected.

She won again this year with A Girl In The River: The Price of Forgiveness, about a teenage girl who miraculously survived an honour killing when her father and uncle shot her in the head, put her in a sack then dumped her in a river for marrying a man they considered unsuitable.

"This is what happens when determined women get together," Obaid-Chinoy declared in one of the Oscars' most powerful acceptance speeches. "This week the Pakistani Prime Minister has said that he will change the law on honour killing after watching this film. That is the power of film."

Soon to head to Australia for the Sydney Film Festival, where she is screening both A Girl In the River and 2015's A Journey Of A Thousand Miles, which is about 160 mostly Muslim women who head to earthquake-damaged Haiti as a UN peacekeeping unit, Obaid-Chinoy says she is motivated both by anger about the issues she confronts and the knowledge that she was lucky to be born into a strong, well-off family.

She grew up in Karachi – one of six daughters and a son with a father who was a successful businessman and a mother who was an administrator at a school for orphans and volunteer for non-profit organisations – then studied economics and political science at Smiths College and Stanford University in the US before returning home to Pakistan.

"It's the luck of the draw that I was born in the family I was born in, that I was able to get an education, that I'm empowered to make decisions about my own life," she says. "But just as easily I could have been born on the other side of the tracks, perhaps into a family that didn't value education, that wanted me to get married early. I wonder then what my choices would have been.

"That's why I think it's very important to fight for people who are unable to fight for themselves, not just by sharing their stories but also by being an advocate for those issues."

But the threats to outspoken women in Pakistan mean her work is "definitely an uphill battle and a lonely one".

That uphill battle began when she decided to become a filmmaker at 21, writing 80 proposals to every production house and news channel she could think of to make Terror's Children, about Afghan children living in the aftermath of war. She eventually produced the film in 2003.

"I got so many 'nos' that it's embarrassing," she says. "I said 'you know what, I'm just going to make the film."

"Right at the end, people came through and funded the film, including The New York Times which had just set up a television entity and part of the funding came from my own college."

Obaid-Chinoy has become an acclaimed filmmaker despite never studying film.

"Everything that I've learned has been on the road," she says. "I taught myself or I've had really fantastic mentors. In terms of my career, the most incredible thing is I've never taken no for an answer.

"I've just gone and knocked on another door. I've had many people say 'that's not going to work' or 'that story is not a story we'd like to fund' but I've always taken that rejection and said 'OK, I just need to knock on another door'.

"Being stubborn and having perserverance goes a long way."

Racism is another obstacle that Obaid-Chinoy has faced.

"I've experienced it in my career," she says. "I did a film many years ago where I worked with a producer who was extremely racist, who wanted all the credit for the film, even though it had been done by myself and the team.

"I've also experienced sexism. But I've never allowed that to dishearten me because for every sexist and racist person, there are 20 who are supportive, who help in any way they can. I've always looked to those 20 to help push me through."

On the issue of honour killings – responsible for the death of more than 1000 women in Pakistan every year – Obaid-Chinoy says the current law that  is being slated for change allows the killers to avoid punishment if they are forgiven by family members.

"If a father kills his daughter, his wife can forgive him," she says. "If a brother kills his sister, the parents can forgive him. It's not a crime against the state. It's a crime against an individual.

"This new law will make it a crime against the state so there will be no forgiveness … If you take away the forgiveness and people start going to jail, people will realise that killing a woman under the guise of honour killings is a serious crime."

Obaid-Chinoy says these types of killings remain prevalent in India and Turkey as well as Pakistan and are happening more frequently.

"To me an honour killing is about power," she says. "It's about patriarchy. It's about 'keeping women in line'.

"If you look at how women are killed in the name of honour in both India and Pakistan, it's all about men trying to control women. And as the world is changing and women are getting educated and are more aware of their rights and pushing, the number of honour killings is going up."

Acid attacks on women, which Obaid-Chinoy says are happening in India, Bangladesh, Pakistan and Colombia, are part of the same urge by men to punish women.

"If you look at cases of acid violence or honour killings and you look at how it's justified, the woman asks for a divorce, the woman said no to her hand in marriage, the woman wanted to get married out of her free will. It all has to do with a woman asking for her rights."

With an in-demand life that includes writing a book about grassroots change, Obaid-Chinoy values her family's role in raising her children.

"My children are brought up by my tribe," she says. "They're not just brought up by me. My tribe is my mother, my grandmother, my sisters, my mother-in-law, my sister-in-law, my husband. We all bring up my children.

"In 2016, if a woman really wants a career, she's got to find a stable family system to bring up her children.

"Otherwise you hit up against the glass ceiling very quickly. I'm one component but I feel like my kids have many mothers and many role models and many people that they spend time with."

The Sydney Film Festival is on June 8-19.