She also had two sisters, Mary and Henrietta and through her father's relationship with Hester Davenport she also had an illegitimate half-brother named Aubrey de Vere.

[5] Diana had been a lady-in-waiting and a favourite of Mary II, who included her among the portrait series known as "The Hampton Court Beauties" During the reign of Queen Anne neither Diana nor her husband were much favoured as Anne, Beauclerk's cousin, did not care much for the illegitimate children of her uncle and regarded the sons with suspicion and as potential usurpers.

Furthermore, Beauclerk's Whig views prevented he and his wife’s advancement, but they were restored to favour at the accession of King George I in 1714.

Subsequently Diana became the first lady of the bedchamber and Groom of the Stool to George I's daughter-in-law Caroline of Ansbach .

In 1714 Diana tried to have her maternal grandmother Mary Kirke considered for the position of "bedchamber woman[6]" but nothing came of it perhaps due to her bad reputation.

[9] She attended the funeral of Caroline of Ansbach in 1737 at Westminster Abbey and carried the train of Princess Amelia alongside the Duchess of Montagu.

Diana died on the 15th of January 1742[13] at Burford HouseThat great and good lady, the late Duchess of St. Alban's, whose memory will be ever precious among us, sweet as honey in the mouths of all that speak of her, and as music at a banquet of wine in the ears of all that hear of her .

She supported a dignity worthy of her high birth; yet was of so condescending, so affable, and so courteous a disposition, that she engaged and won the hearts of all who were admitted into her presence.