Laetitia Van Lewen was born in about 1708 in County Cork. Her father, Dr. John Van Lewen, was a physician. Her mother, Elizabeth Corry Van Lewen, came from a distinguished family (her great grandfather was the Earl Of Killmallock).
In 1725 Laetitia married Matthew Pilkington. Soon afterwards the couple was introduced to Jonathan Swift at St. Patrick's Cathedral, Dublin. They became close friends and Swift and in 1732 he helped Pilkington to become appointed as chaplain to the Lord Mayor of London.
Matthew Pilkington became involved with a Drury Lane Theatre actress whereas Laetitia began involved in a relationship with a young surgeon, Robert Adair. When Pilkington discovered the relationship he divorced his wife.
Laetitia Pilkington now attempted to make a living from writing. She sold her poetry to James Worsdale and Colley Cibber, who passed it off as their own work. Laetitia also helped Samuel Richardson with his novel, Clarissa. In 1737, she wrote a feminist prologue for Worsdale's A Cure for a Scold as well as a opera called No Death but Marriage.
In 1742 Laetitia Pilkington was arrested for a two pound debt and imprisoned in the Marshalsea gaol and was only released with the help of Samuel Richardson.
Laetitia Pilkington now began work on her memoirs. Matthew Pilkington worked hard to ensure that the book was not published in London. Other writers such as Colley Cibber and Samuel Richardson refused to help fearing their activities would be exposed in her book. Unable to find a publisher for her work, Laetitia moved back to Dublin. The first two volumes of her Memoirs appeared in 1748.
Laetitia Pilkington died on 29th July, 1750. her son, John Carteret Pilkington, arranged for the third volume of her Memoirs to be published in 1754.