Adelaide Martens was born in London, England, on 6 March 1845, the daughter of Elizabeth Ann Joyner and her husband, George Martens, a sugar baker. Nothing is known of her early life. She is believed to have arrived in New Zealand from Australia in 1862 on the Arabia. She served as a stewardess on the wind-jammers and early coastal steamers between Lyttelton and Bluff.
Adelaide Martens probably met her future husband, Henry Hicks, on a voyage south on the Flying Mist. He was an American of mixed European and African ancestry, who acted as chief cook and steward on many of the coastal ships. At the time of their marriage in Invercargill on 8 August 1864, Henry was a publican. Shortly afterwards they moved to Dunedin, where Henry resumed work on the ships and Adelaide took up domestic work. The couple were to have nine children. Around 1879 they moved to the Mosgiel bush area, where Henry started a firewood-cutting business.
On 17 May 1884, when the youngest of their children was only 18 months old, Henry Hicks was kicked in the abdomen by his horse; he died of an internal haemorrhage the next day. Adelaide was left to bring up seven girls and two boys in a harsh rural environment. Shortly after Henry's death the Silver Stream flooded, and she was forced to assemble her family on top of the kitchen table to prevent the children being drowned.
In 1886 Adelaide Hicks moved to Factory Road, Mosgiel. There she opened a maternity home, which became the first registered in the area. Adelaide became known as 'Nurse Hicks', and although she possessed no formal nursing training was regularly called on in times of medical and social crisis. Her midwifery took her into the small local community and out into the district, where she attended confinements. She was helped in these duties by several of her daughters.
Despite being a diminutive, refined woman, Adelaide Hicks was known for her ability to deal with a variety of medical emergencies and tasks. On one occasion she was called on to attend to the dead from a railway accident in which men working in the Wingatui tunnel had been hit by a train. A neighbour described her as having nerves of steel. She worked as a volunteer nurse during the influenza epidemic of 1918, for which she was subsequently recognised by the Otago Hospital and Charitable Aid Board. Her high public profile in Mosgiel also saw her take on the role of unpaid social worker, particularly among the workers at the Mosgiel Woollen Factory Company. On 3 June 1922, while visiting her two brothers in England, she was received by Queen Mary at Buckingham Palace, on the occasion of the ceremony of Trooping the Colour on the official birthday of King George V.
In 1927 Adelaide Hicks signed over her maternity home to her daughter Edith, who maintained it for several years. Adelaide remained at Factory Road, where she died of heart failure on 20 May 1930 at the age of 85. She was celebrated as a pioneer woman whose courage in emigrating alone to New Zealand as a teenager typified the spirit she brought to the small community of Mosgiel.