Dorothy first came to court in 1540, where she served as a Maid of Honour to Anne of Cleves, fourth wife of Henry VIII. When that marriage was annulled, Dorothy went on to serve in the same capacity, Anne's successor, Catherine Howard, whom the King had married in July 1540. In 1541, Dorothy embarked on a love affair with William Parr, Baron Parr of Kendal, who would later hold the title of 1st Marquess of Northampton, after Baron Parr's wife, Anne Bourchier, 7th Baroness Bourchier had created a scandal when she ran off with her lover, John Lyngfield, and shortly afterwards bore him an illegitimate child. Dorothy's affair with Parr lasted until 1543, when he began to court her niece, Elizabeth Brooke, who had also been one of Catherine Howard's Maids of Honour up until the Queen's execution for High treason. It was during that time that King Henry himself was courting Parr's sister, Catherine, whom he married in July. Dorothy entered the new Queen's household as one of her Maids of Honour.
Marriages and issue
Sometime in about 1546, she married her first husband, Edmund Brydges, son of John Brydges, 1st Baron Chandos. Together they had five children:
Mary Brydges
Katherine Brydges, married Sir William Sands, Lord Sandes of the Vine, by whom she had one daughter, Elizabeth.
On 12 April 1557, when her husband succeeded to his title, Dorothy was styled Baroness Chandos; in later years, she became known as "Old Lady Chandos". They made their home at Sudeley Castle in Gloucestershire. On 11 March 1573, Edmund died and he was succeeded by their eldest son, Giles. The following year, Queen Elizabeth visited Dorothy at Sudeley Castle. Her second husband, William Knollys MP, was considerably younger than Dorothy. The date of their marriage was not recorded. A portrait of a woman painted by John Bettes the Younger in about 1578, is allegedly that of Dorothy.
Death
Dorothy died in Minty, Gloucestershire, on 31 October 1605 at the age of 81. She was buried in Rotherfield Greys Church, Oxfordshire, where her effigy can be seen. Her grandson Grey Brydges, 5th Baron Chandos inherited her estate. Less than two months after Dorothy's death, William Knollys married his second wife, Lady Elizabeth Howard. It was uncertain as to whether Elizabeth's two sons were fathered by William, and as a result they were not permitted to take their seats as Earls of Banbury in the House of Lords.