Harriet was born the first child of Jeremy Blackwood and Josephine Blackwood. She experienced a very isolated childhood as her parents attempted to live outside of the public eye. Until meeting Russell Charbonneau in 2019, Harriet had only spent time with her father, mother, younger brother Theodore and the handful of staff within her home. She was taught by a private tutor in the family home and rarely left the grounds.

From a young age, Harriet experienced sexual abuse from her father. Harriet became very protective of her brother, Theodore, when he was born, fearing he would also experience the abuse.

As a child, Harriet's mother passed away due to illness and later, during her teenage years, her brother also passed away due to illness.

On Harriet's 16th Birthday, her father announced his plan to marry her, so Harriet could take her deceased mother's place in the family. This engagement was called off, however, as in 2019, Russell Charbonneau asked Harriet's father for her hand in marriage.

Following Harriet's marriage to Russell, Harriet and her father moved into the Charbonneau estate, with Jeremy leaving upon the birth of Harriet's first child, Florence Charbonneau in 2023. Harriet and Russell went on to have another daughter, Felicity Charbonneau, and a son, Marcus Charbonneau II.