On the night of 7 February 2017, in the Chilean coastal city of Concepción, Antonia Garros Hermosilla visited her ex-boyfriend, Andrés Larraín Páez, a man who had allegedly been abusive throughout their tumultuous two-year relationship.

Hours later, the 23-year-old fell to her death from the balcony of her ex-boyfriend’s home. The Chilean police and judiciary ruled that the death was an unassisted suicide. The family believe she was assaulted before she fell, and there is witness testimony suggesting Antonia was attacked by her boyfriend.

On Wednesday, events will be held in Concepción to mark the first anniversary of Antonia’s death. Her mother, Consuelo Hermosilla, is campaigning for a change in the law to penalise causing suicide through extreme physical and psychological aggression in non-cohabiting relationships.

The draft bill, which notes that similar laws exist in Spain, Mexico, Brazil, Colombia, Argentina and the UK, calls for a maximum prison sentence of five years for those found guilty.

Antonia Garros Hermosilla Photograph: Courtesy of ​Consuelo Hermosilla

The bill has so far failed to garner significant support, but Consuelo and her supporters are hopeful it will establish greater momentum after a new parliament is sworn in next month.

However, in a country where the prevailing macho culture means a blind eye is often turned to violence against women, and where reports of abuse are often met with indifference from the police and judiciary, getting the measure passed could be difficult.

In a national survey carried out by Chile’s interior ministry between December 2016 and March 2017, 38% of women aged between 16 and 65 said they had experienced some form of psychological, physical or sexual violence. Another survey, conducted by the National Youth Institute in 2016, found that half of young people aged 15 to 29 knew someone who had experienced some form of violence from a partner during the previous 12 months.

Last year, the Chilean Network against Violence towards Women registered 67 cases of femicide (women murdered because they are women).

Investigations into Antonia’s death were wound up on 12 January by a lower-court judge, who concluded that no third parties were involved and her suicide had been unprovoked while noting that Chile has no law for driving someone to suicide. The family is appealing against the decision.

Antonia’s mother, who set up the Antonia Foundation to provide support and counselling to survivors of abuse, said: “I swear that during what’s left of my life, I’ll do all I can to combat this brutality and teach people not to take violence against women for granted … and to demand justice for my daughter Antonia.”

Facebook Twitter Pinterest A woman holds a card reading ‘Beware, male chauvinism kills’ at a demonstration against femicide in Santiago, Chile. Photograph: Martin Bernetti/AFP/Getty Images

Philosopher and women’s rights activist Ximena Riffo, of the #NiUnaMenos (#NotOneWomanLess) collective, said the proposed legislation would help to highlight the often unrecognised level of systematic violence against women and girls. “The law as it is simply doesn’t provide enough protection to women, in Chile or the rest of Latin America,” she said.

However, Giorgio Jackson, one of the MPs who helped draft what has become known as “Antonia’s Law”, blamed the lukewarm response form Chilean lawmakers on the potential challenges of its implementation.

“Relationships are complex … [and] cases of abuse are frequently not reported. And even if we pass this law, when such a case comes up in court it’s very difficult to prove,” he said. “Criminal law is based on the presumption of innocence. When there’s one testimony versus another, and no other available evidence, no judge is going to risk sentencing a person to a jail term if he or she feels any doubt.”

But he added: “It would represent a symbolic, cultural sign to encourage people to maintain relationships in a different way, and of course there’d have to be prevention campaigns in the media. If the law changes, hopefully the Carabinero police will pay more attention to this issue.”

In November, in Antonia’s memory, the Chilean lower house of Congress approved a resolution to make 7 February the National Day of Non-Violence in Courtship Relationships. The resolution awaits the approval of the country’s Senate.

• International suicide helplines can be found at www.befrienders.org. In the UK, Samaritans can be contacted on 116 123. In the US, the National Suicide Prevention Lifeline is 1-800-273-8255. In Australia, the crisis support service Lifeline is 13 11 14.