Henrietta was one of three daughters of Sir Henry Hobart, 4th Baronet, a Norfolk landowner, and his wife Elizabeth (née Maynard).

Henrietta met and became mistress to his son, the future George II, and was appointed a Lady of the Bedchamber to his wife, Caroline of Ansbach.

In 1723, the now Prince of Wales made a financial settlement with her husband, who was also a member of his household,[2] in exchange for her services as a royal mistress.

After George II moved on to a new mistress, Amalie von Wallmoden in 1734, Henrietta purchased land on the banks of the River Thames, having received a very large financial settlement from the King.

She formed an intellectual circle, and her many friends included Charles Mordaunt, 3rd Earl of Peterborough, John Gay, and Alexander Pope.