question: Who is the mother-in-law of Agnes Leslie, Countess Of Morton?
context: [["Priscilla Pointer", ["Priscilla Marie Pointer( born May 18, 1924) is an American stage, film and television character actress.", "She began her career in the theater, including productions on Broadway.", "Later, Pointer moved to Hollywood to act in films and on television.", "She is the mother of Amy Irving, therefore making her the former mother- in- law of filmmakers Steven Spielberg and Bruno Barreto and the mother- in- law of documentary filmmaker Kenneth Bowser, Jr."]], ["Vera Mileti\u0107", ["Vera Mileti\u0107 (Serbian Cyrillic: \u0412\u0435\u0440\u0430 \u041c\u0438\u043b\u0435\u0442\u0438\u045b; 8 March 1920 \u2013 7 September 1944) was a Serbian student and soldier.", "She was notable for being the mother of Mira Markovi\u0107, posthumously making her the mother-in-law of Serbian president Slobodan Milo\u0161evi\u0107."]], ["Agnes Leslie, Countess of Morton", ["Agnes Leslie, Countess of Morton (born after 1541 \u2013 c. 1606) was a Scottish noblewoman, being the daughter of George Leslie, 4th Earl of Rothes as well as a direct descendant of King James II in her maternal line.", "She was the wife of William Douglas, 6th Earl of Morton, who as Laird of Lochleven Castle was the custodian of Mary, Queen of Scots during her captivity from June 1567 until her escape on 2 May 1568.", "Agnes was Queen Mary's chief female companion throughout her imprisonment; thus it was while Lady Agnes was recovering from childbirth that the queen successfully escaped from Lochleven."]], ["Eldon Howard", ["Eldon Howard was a British screenwriter.", "She was the mother- in- law of Edward J. Danziger and wrote a number of the screenplays for films by his company Danziger Productions."]], ["William Douglas, 9th Earl of Morton", ["William Douglas, Earl of Morton (died before 1 November 1681) was a Scottish nobleman and Earl of Morton.", "He was the son of Robert Douglas, 8th Earl of Morton and Elizabeth Villiers.", "He succeeded as the 9th Earl of Morton on 12 November 1649.", "William tried to preserve the grant of the Islands of Orkney and Zetland which had been given to his grandfather, Sir William, 7th Earl of Morton.", "The wadset (a loan masked as a sale of land under right of reversion) of the Lordship had been set aside, and annexed to the Commonwealth in 1657.", "On the Restoration, he obtained a new grant, which confirmation was ratified by Parliament in 1661.", "However, this too was pronounced null and void, and the islands were vested in the Crown by Act of Parliament on 27 December 1669.", "Thenceforward the Earls of Morton held these islands under a form of mortgage from the Crown.", "On 9 September 1672 he resigned the Barony of Dalkeith in favour of James, the Duke of Buccleuch.", "The estate of Dalkeith and other lands, to the total value of \u00a3100,000 Scots yearly rental, had been sold circa 1643 to Buccleuch to enable the 7th Earl meet his expenses supporting the King.", "William married Grizel, daughter of John, Earl of Middleton, in 1662.", "Their only son, Charles, Lord Dalkeith, died in infancy in 1663.", "William died in 1681 leaving no heir, passing the Earldom to his uncle, James Douglas, 10th Earl of Morton who was the son of William Douglas, 7th Earl of Morton and Lady Anne Keith."]], ["Marian Shields Robinson", ["Marian Lois Robinson( n\u00e9e Shields; born July 29, 1937) is the mother of Michelle Obama, former First Lady of the United States, and Craig Robinson, a basketball executive, and the mother- in- law of former U.S. President Barack Obama."]], ["Maria Thins", ["Maria Thins( c. 1593 \u2013 27 December 1680) was the mother- in- law of Johannes Vermeer and a member of the Gouda Thins family."]], ["William Douglas, 6th Earl of Morton", ["William Douglas, 6th Earl of Morton (c. 1540 \u2013 1606) was the son of Sir Robert Douglas of Lochleven and Margaret Erskine, a former mistress of James V of Scotland."]], ["Joan Stewart, Countess of Morton", ["Joan Stewart, Countess of Morton, also called Joanna( c. 1428 \u2013 22 June 1493), was the daughter of James I, King of Scotland, and the wife of James Douglas, 1st Earl of Morton.", "She was known, in Latin, as the\" muta domina\"[ mute lady] of Dalkeith."]], ["Robert Douglas, 8th Earl of Morton", ["Robert Douglas, Earl of Morton( died 12 November 1649) was a Scottish nobleman and Earl of Morton.", "He was the son of William Douglas, 7th Earl of Morton and Lady Anne Keith, daughter of George Keith, 5th Earl Marischal.", "In 1627, he married Anne Villiers, a daughter of Sir Edward Villiers."]]]
supporting_facts: [["Agnes Leslie, Countess of Morton", 1], ["William Douglas, 6th Earl of Morton", 0]]
evidences: [["Agnes Leslie, Countess of Morton", "spouse", "William Douglas, 6th Earl of Morton"], ["William Douglas, 6th Earl of Morton", "mother", "Margaret Erskine"]]
answer: Margaret Erskine