Ann Gleeson was born in the village of Adare, County Limerick, Ireland, probably some time between 1827 and 1831, to Ann Roberts and her husband, Patrick Gleeson, a farmer. The Gleeson family was comfortably off, and their daughter was educated at the Ursuline convent in Dublin. It was perhaps a spirit of adventure, certainly not poverty, which prompted her to emigrate to Melbourne, Australia, in 1858 with her cousin, Johanna Shanahan, and close friend Mary Maloney. On 7 December 1859 at St Kilda, Melbourne, Ann Gleeson married Patrick Diamond, a stonemason from Belfast. She gave birth to her first child, Rosanna, in 1861, and in 1862 sailed with her husband, child, cousin and friend to Dunedin, New Zealand. Patrick joined the Gabriels Gully goldrush while Ann, with Johanna and Mary, ran a boarding house in Dunedin. There she gave birth to her second daughter, Mary Jane. She also learnt midwifery skills from a young doctor who boarded with 'the Limerick girls', as Ann, Johanna and Mary were known.
In mid 1865 they all set sail for Greymouth. They soon shifted inland to the Red Jacks locality, where gold had been discovered in July. Ann and Patrick were the first married couple to arrive at the isolated settlement of Red Jacks, and with Johanna and Mary's help they set up a general store and hotel. Ann Diamond refused to live in a shanty town shack. Not one to compromise once her mind was made up, she lived in tents for six rainy months until the nine room hotel was built. Diamond's hotel soon became the centre of social life for the local population. Ann Diamond had a concert hall and billiard saloon built so that the miners, who otherwise tended to drink to excess, could be entertained. A visiting priest, impressed with the high standard of accommodation, gave her a French harmonium, which was often used in the concert hall.
During the frequent floods and snowstorms, Ann Diamond had to accommodate miners and their families in the hotel temporarily. She always felt sorry for women in 'reduced circumstances' on the goldfields, so some stayed for long periods, becoming almost part of the family. She was kept busy running the store almost single-handed, supervising the hotel work, carrying endless supplies of wood and water, and answering frequent midwifery calls, which often came late at night. In addition she had to cope with the demands of her own growing family: two sons, James and John, were born at Red Jacks. Her one extravagance was having beautiful clothes made for her daughters by seamstress and milliner Mary Maloney. Ann loved dressing up and welcoming visitors, though her daughters thought her insistence on Victorian etiquette a little unnecessary in the bush.
From 1874 Ann Diamond ran the hotel alone. Mary Maloney and Johanna Shanahan had both married, but Ann still saw them regularly and delivered many of their children. The three women had lived together harmoniously since the late 1850s, as business partners and friends. They had complementary talents and characters, and never did anything without consulting one another. Friendship may have compensated Ann Diamond for some of the sorrow she endured as a mother. She never got over Rosanna's death from diphtheria in 1875, and she never forgave Mary Jane for eloping in 1880, although she saved her life at the birth of her first child in 1881.
Ann Diamond died on 22 April 1881 at Red Jacks. She had strained herself lifting supplies and died from a strangulated hernia, at the hotel where she had worked so hard.