Born on 22 June 1769 in Streatham, and Christened on 16 July 1769 at St. Leonard's Church, Streatham. She was described as a sickly child but also abundant in softness and kindness.

She acquired her name after Johnson insisted on her being called Elizabeth, in Memory of his late wife Elizabeth (known as 'Tetty). Lucy was a very pretty and "wonderfully active with her feet" although not very talented concerning matters of grammar and English.

Lucy died aged four on 22 November 1773 due to a brain abscess caused by an inflammation of both middle ears and mastoids resulting from a cold. She was buried on 26 November 1773 at St. Leonard's Church, Streatham without any monument.