A court in Northern Ireland has acquitted a woman who was prosecuted for buying online abortion pills for her daughter, after the decriminalisation of abortion in the region.

The judge, David McFarland, directed a jury at Belfast crown court on Wednesday to find the woman not guilty a day after Northern Ireland’s Victorian-era abortion laws were liberalised. The prosecution offered no evidence.

“My emotions are all over the place. I find it hard to put into words how I am feeling,” the woman, who cannot be named for legal reasons, said after the verdict. “For the first time in six years I can go back to being the mother I was without the weight of this hanging over me every minute of every day. I am so thankful that the change in the law will allow other women and girls to deal with matters like this privately in their own family circle.”

She added: “I can finally move on with my life.”

The woman bought and supplied abortion pills in 2013 to her then 15-year-old daughter, who terminated the pregnancy.

After her GP alerted police the Public Prosecution Service for Northern Ireland levelled two charges of unlawfully procuring and supplying abortion pills with the intent to procure a miscarriage contrary to the 1861 Offences Against the Person Act. The decision to subject her to a criminal trial and the prospect of five years in prison provoked an outcry and intensified campaigners’ efforts to align Northern Ireland’s abortion laws with the rest of the UK.

The campaign led to a vote by MPs in July to extend abortion rights to the region. The legislation – along with legalisation of same-sex marriage – took effect on Tuesday. It put a moratorium on criminal prosecutions, halting police investigations into abortion cases. The law also obliges the UK to ensure regulations for free, legal and local abortion services are in place by 31 March 2020.

The woman’s solicitor, Jemma Conlon, said her client was immensely relieved that a six-year legal ordeal had ended. “It is a day that she will forever remember and a day that allows her to finally move on with her life privately without anguish and criminalisation,” she said.

Grainne Teggart, Amnesty International’s Northern Ireland campaign manager, said no other women would be hauled through the courts and face criminal prosecution in the manner the acquitted woman had been. “This is the beginning of a more caring and compassionate Northern Ireland,” she said.

The Democratic Unionist party (DUP) and other anti-abortion parties attempted to recall the mothballed assembly at Stormont on Monday to avert decriminalisation. The gathering – the first at Stormont in almost three years – collapsed in acrimony and the legislation went ahead. The DUP leader, Arlene Foster, said her party would examine ways to repeal it. “We will do everything in our conscience to protect the lives of the unborn,” she said.

The breakdown of relations between the DUP and Sinn Féin, which favours abortion rights, has stymied efforts to restore the power-sharing assembly.