Susan Ann Lacy was born c. 1820, the daughter of Colonel J. Dacre Lacy. She married Dr William Gull on May 18th, 1848. Together they moved to 8 Finsbury Square. They had three children together, two of whom survived to adulthood. Their first child, Caroline Cameron Gull, was born in 1851. The second, Cameron Gull, was born in 1858, and died in infancy. The third, William Cameron Gull, was born in 1860. When her husband was given the title of 1st Baronet of Brook Street in 1872, she was given the title of Dame.
When her husband died in 1890 she was bequeathed a great deal of money, as well as the house that they had shared. She died four years later in 1894. She was 74 years of age.