Question: Name the mother of Edward Stafford, 4th Baron Stafford, who was the daughter of the English nobleman and politician Edward Stanley, 3rd Earl of Derby?
Context: Henry Stafford, 1st Baron Stafford (18 September 1501 – 30 April 1563) was born in Penshurst, Kent, eldest son of Edward Stafford, 3rd Duke of Buckingham and Eleanor Percy, Duchess of Buckingham.  Eleanor (or Alianore) was the daughter of Henry Percy, 4th Earl of Northumberland and Maud Herbert, Countess of Northumberland.  After his father's execution he managed to regain some of his family's position and he was created Baron Stafford in 1547. Edward Stafford, 3rd Baron Stafford (7 January 1535 – 18 October 1603) was the second surviving son of Henry Stafford, 1st Baron Stafford and Ursula Pole, the younger brother of Henry Stafford, 2nd Baron Stafford.  He served in Parliament for Stafford and succeeded his brother to the barony in 1566. Admiral Edward Stafford Fitzherbert, 13th Baron Stafford, KCB (17 April 1864 – 28 September 1941) was an English peer, holding the title Baron Stafford.  He was also a Royal Navy officer who went on to be Commander-in-Chief, Cape of Good Hope Station. The Jerningham Baronetcy, of Cossey in the County of Norfolk, was a title in the Baronetage of England.  It was created on 16 August 1621 for Henry Jerningham.  The fifth Baronet married Mary, only daughter of Mary Plowden, sister of John Paul Stafford-Howard, 4th Earl of Stafford and de jure 5th Baron Stafford (see the Baron Stafford 1640 creation).  He was succeeded by his son, the sixth Baron.  In 1807 the claim to the barony of Stafford, which had been under attainder since 1680, passed to him through his mother.  He died in 1809 when the baronetcy and the claim to the barony passed to his son, the seventh Baronet.  He petitioned the House of Lords for a reversal of the attainder of the barony of Stafford and for a writ of summons to Parliament.  In 1824 the attainder was reversed and the following year he was summoned to the House of Lords as the eighth Baron Stafford. Edward Stourton, 10th Baron Stourton (c. 1555-7 May 1633) was a younger son of Charles Stourton, 8th Baron Stourton and Lady Anne Stanley, daughter of Edward Stanley, 3rd Earl of Derby.  His father was executed for murder in 1557.  He succeeded his brother John in 1588. Henry Nevill, 6th and "de jure" 4th Baron Abergavenny KB (between 1527 and 153510 February 1587) was an English peer.  He was the son of Sir George Nevill, 5th Baron Bergavenny, and Mary Stafford (daughter of Edward Stafford, 3rd Duke of Buckingham).  He succeeded to the barony upon the death of his father, George Nevill, 5th Baron Bergavenny. John Talbot, 3rd Earl of Shrewsbury, 3rd Earl of Waterford, 9th Baron Talbot, KG (12 December 1448 – 28 June 1473) was an English nobleman.  He also held the subsidiary titles of 12th Baron Strange of Blackmere and 8th Baron Furnival.  Although a soldier and an administrator, he was described by William of Worcester as 'more devoted to literature and the muses, than to politics and arms'. Baron Stanley of Alderley, in the County of Chester, is a title in the Peerage of the United Kingdom.  It was created in 1839 for the politician and landowner Sir John Stanley, 7th Baronet.  Upon his death in 1850, he was succeeded as 2nd Baron Stanley of Alderley and 8th Baronet of Alderley Hall by his son Edward, who was a prominent Liberal politician and notably served as President of the Board of Trade, Postmaster General and had in 1848 been created Baron Eddisbury, of Winnington in the County Palatine of Chester, in his own right.  His wife Henrietta was a prominent campaigner for women's education.  After his death, the Stanley of Alderley and Eddisbury baronies remained united; most holders have since chosen to be known as "Lord Stanley of Alderley".  The 3rd Baron Stanley of Alderley had a career in the Diplomatic Service; as he was childless he was succeeded by his younger brother, the 4th Baron.  He was Liberal Member of Parliament for Oldham.  In 1909, the 4th Baron Stanley of Alderley acquired a further title when he succeeded his first cousin once removed, the Earl of Sheffield, according to a special remainder and thus inherited the title of 4th Baron Sheffield.  After his death the titles passed to his son, the 5th Baron Stanley of Alderley.  He was Liberal Member of Parliament for Eddisbury and also served as Governor of Victoria.  His eldest son, the 6th Baron Stanley of Alderley, sold the family seat of Alderley Hall in 1938.  He was married four times, the second time to Sylvia Ashley.  On his death the titles passed to his younger brother, who preferred to be known as Lord Sheffield.  He only held the titles for three months.  s of 2013 the titles are held by the latter's cousin, the 9th Baron Stanley of Alderley, who succeeded his father in that year.  He is the grandson of the Hon. Oliver Hugh Stanley, youngest son of the 4th Baron. Edward Stafford, 4th Baron Stafford (1572 – 16 September 1625) was the son of Edward Stafford, 3rd Baron Stafford and Mary Stanley, daughter of Edward Stanley, 3rd Earl of Derby and Dorothy Howard.  He became 4th Baron Stafford on the death of his father in 1603 Edward Stanley, 3rd Earl of Derby KG (c. 10 May 1509 – 24 October 1572) was an English nobleman and politician.
Answer: Mary Stanley