Daughter of King Friedrich Wilhelm I (1688-1740) of Prussia and Sophia Dorothea (1685-1757). Sister of King Frederick II the Great. Married (1733) to Charles I.
She was known as a well-educated and much-respected lady, who, at her death, left her collection of 4,000 volumes to the Wolfenbüttel Library.
Boswell was introduced to the Duchess at the Court of Brunswick on June 27, 1764.