Margaret Cooper was baptised on 2 April 1807 at Fraserburgh, Aberdeenshire, Scotland. She was the daughter of Elizabeth Ross and her husband, Robert Cooper, a farmer. On 3 July 1830 she married Robert Forbes at Pitsligo, Aberdeenshire. Margaret and Robert Forbes and their six children arrived in Wellington, New Zealand, on the Slains Castle on 25 January 1841. They settled at Epsom, Auckland, where Robert became the innkeeper of the One Tree Hill Inn. The Forbes family were the first Presbyterian Scottish settlers to live in the area. A daughter, Jessie, was born there on 30 March 1842.
In 1844 the family moved to Onehunga, where Robert Forbes applied for and was granted a bush licence. He established the New Leith Inn, near the beach, in a large raupo dwelling which had once been used by Ngati Mahuta leader Potatau Te Wherowhero. This was the first licensed accommodation established in Onehunga. In 1845 Robert Forbes was able to buy direct from the Maori owners, Te Keene, Te Hira Te Kawau and Te Moana, the eight acres surrounding his inn. The purchase was allowed under the terms of a proclamation issued by Governor Robert FitzRoy on 24 June 1844 which waived the Crown's pre-emptive rights.
On 10 November 1844 a daughter, Isabella, was born. Margaret Forbes by now had a large family to care for and was also called on to assist her husband in the running of the inn. To meet the demands of travellers and the needs of the family, larger premises were built in 1846.
In 1846, under the direction of Governor George Grey, an ordinance was passed by the Legislative Council restoring the Crown's pre-emptive rights. Commissioners were instructed to question the validity of all claims to land purchased direct from Maori, and consequently Robert Forbes was required to submit a claim for his land. In 1847 Commissioner Henry Matson recommended that a grant be given, but Robert Forbes died on 7 April 1849, before the title deeds had been issued.
By the end of 1849 Margaret Forbes was engaged in a bitter dispute with the governor, who had proceeded, under the ordinance, to deprive her of most of her land. Government surveyors were sent to her property to peg out the Crown grant of 1½ acres that Grey had personally decided she could retain. Incensed by this intrusion, she ordered them off her land, pulled up the pegs and tore down the boundary flags. She ignored the surveyor general's threats of prosecution for obstruction and resolved to petition the Legislative Council for restitution of her 6½ acres, or compensation. She then visited the governor's residence and asked for permission to address the Legislative Council on her own behalf. When Grey refused, she took him to task, calling him a cold-hearted dictator.
In the end her petition was presented by F. W. Merriman at the Legislative Council meeting held on 20 August 1849. Margaret Forbes received much sympathy and support from influential members of the community and the Auckland Provincial Council, one of whom denounced Grey's treatment of her as 'arbitrary, unprincipled and despotic'. The petition was declined: Grey refused to change his decision, maintaining that the land, which had substantially increased in value, was needed for public purposes. However, it is more likely that the government saw an opportunity to add to its revenue: the land was later put up for auction. Margaret Forbes was able to buy back several allotments when other buyers, knowing of her plight, either sold her the land they had purchased, or refrained from bidding.
On 1 July 1856 the petition was presented again to Parliament by Hugh Carleton, MHR for Bay of Islands. No action was taken and no compensation was offered. Margaret Forbes sold her liquor licence about 1857 and thereafter farmed her land and supported her six surviving children by selling milk, butter and produce. She died on 13 January 1877 at her Onehunga residence.
Margaret Forbes was a courageous, independent-minded woman, devoted to the welfare of her family. She was unusual in that she dared to stand up for her rights before the highest authorities. She lost the battle for justice but went on, against great odds, to provide for her children, and, after years of poverty and hardship, to achieve some prosperity.