Helen McRae Mowat was born on 26 October 1850, the eldest child of Marjory (May) McRae and her husband, Alexander Mowat, a sheepfarmer at Altimarlock station in the Awatere valley, Marlborough, New Zealand. Her early diaries show her to be a diligent if rather impersonal recorder of the daily activities at Altimarlock: the weather, the farm work being done, and the comings and goings of visitors, many of them relatives, often on their way to or from the neighbouring property of Blairich. On 1 September 1874 at Altimarlock Helen Mowat married Henry Joseph Stace, an Englishman from a military family. He was manager of Starborough station (later the location of Seddon) where the Staces spent their early married years. They were to have two daughters and six sons, one of whom died in infancy.
In 1886 Henry Stace bought a property at Robin Hood Bay at the entrance to Port Underwood, Marlborough, then accessible only by boat but later also by pack track from Rarangi to the south. With six children of primary school age, Henry and Helen were entitled to half the salary of a teacher, paid by the Marlborough Education Board. As the older children moved on, sons of friends were invited to make up the required number. Thus the isolated Robin Hood Bay Public School became a boarding establishment for boys, and as its reputation spread, it attracted students from as far afield as Auckland and Dunedin. The average number of pupils at any one time varied between six and 10. The two Stace daughters were the only girls ever on its roll. The presiding force was Helen Stace, a big woman nearly six feet tall, who was said to be an excellent organiser. She was more of a manager than her title of matron implied. When farming times were hard and wool prices low, the school provided the main family support.
A separate schoolhouse was built and running the school became largely a family affair. Bertha, the younger daughter, was for many years her mother's mainstay and the elder daughter, Alice, taught music and dancing. Bread was baked weekly in a large outside oven.
The schoolboys were treated as part of Helen Stace's family. They were expected to take their turn at household chores: chopping wood, milking the cows, churning butter, and killing and dressing sheep. They became skilled in swimming, fishing, sailing, rowing, bushcraft, and pig hunting. For the five-mile boat trip round the cliffs to and from Rarangi, some of the older boys took the oars. The sole-charge teachers employed included some highly educated Englishmen, who for reasons such as a weakness for alcohol had been dispatched to the colony and were able to offer their pupils an almost classical education. By the time the school closed in 1917 after 21 years, a total of 163 boys, including the poet D'Arcy Cresswell, had experienced its invigorating life.
Helen Stace and her husband then sold the property and retired to Picton. She is remembered by her grandchildren as having been a large and somewhat daunting presence when presiding over family occasions like Christmas gatherings. She died in Lister Private Hospital, Blenheim, on 19 January 1926, her husband having died two years earlier. All but one of the five surviving sons lived to be over 80; the two daughters lived to more than 100.