Henrietta was born at St George's Bay, Auckland, on 15 November 1845, during the family's years in the colonial capital, and grew up at Grove Cottage when her parents returned to Waimate in 1846. She was the youngest child to survive to adulthood, and in her old age she became the family's most vivid chronicler.
Her 1914 letter — written when she was nearly seventy — is one of the most beautiful documents in this family archive. It records childhood at Grove Cottage with extraordinary texture: the willow tree that had to be felled for the new dining room; her father walking the sitting-room floor at night, singing her to sleep; the arrival of the piano from England and the unbearable wait until Monday to open it; the old Māori woman Te Rina, brought north as a slave by Hongi Hika and who lived out her life in the Clarke household; the Sunday evenings when the whole family sang together around the piano while Henrietta crept under the table and cried, for reasons she herself couldn't explain.
"He had a wonderful gift in talking to children," she wrote of her father. "He loved them and they knew it and were attached to him."
Henrietta lived in later years at Victoria Avenue and Norana Avenue in Remuera, Auckland. In 1911 she sold "Rarere," the Kerikeri property. She died on 20 October 1923, aged seventy-seven, and was buried at Purewa.