In September 1706, William Cowper secretly married the beautiful 20-year-old Mary, daughter of John Clavering, of Chopwell, Durham after his first wife died in 1705.

In November of the same year, her husband succeeded to his father's baronetcy and in December he was raised to the peerage as Baron Cowper of Wingham, Kent.

The Queen came to have a high regard for Cowper: she valued his advice and, due to his exceptionally youthful appearance, called him "her schoolboy".

The first day she attended the Princess she gave her Bernstorff’s 'A Treatise on the State of Parties' which she 'had transcribed and translated for my Lord, in French and English, to give the King.'

[3] She could write vividly and with a dry wit, as when describing the unfortunate marriage of John Hartstonge, Bishop of Derry to Isabelle Danvers, a lady of the Royal Bedchamber.