Sibylla of Anjou
Sibylla of Anjou (c. 1112–1165) was a countess consort of Flanders.
She was the daughter of Fulk V of Anjou and Ermengarde of Maine, and wife of William Clito and Thierry, Count of Flanders.
She was the regent of Flanders in 1147-1149.
In 1123 Sibylla married William Clito, son of the Norman Robert Curthose and future Count of Flanders.
Sibylla brought the County of Maine to this marriage, which was annulled in 1124 on grounds of consanguinity.
The annulment was made by Pope Honorius II upon request from Henry I of England, William's uncle; Fulk opposed it and did not consent until Honorius excommunicated him and placed an interdict over Anjou.
Sibylla then accompanied her widower father to the crusader Kingdom of Jerusalem, where he married Melisende, the heiress of the kingdom, and became king himself in 1131.
In 1139 she married Thierry, Count of Flanders, who had arrived on his first pilgrimage to the Holy Land.
She returned to Flanders with her new husband, and during his absence on the Second Crusade the pregnant Sibylla acted as regent of the county.
Baldwin IV, Count of Hainaut took the opportunity to attack Flanders, but Sibylla led a counter-attack and pillaged Hainaut.
In response Baldwin ravaged Artois.
The archbishop of Reims intervened and a truce was signed, but Thierry took vengeance on Baldwin when he returned in 1149.
In 1157 she travelled with Thierry on his third pilgrimage, but after arriving in Jerusalem she separated from her husband and refused to return home with him.
She became a nun at the Convent of Sts.
Mary and Martha in Bethany, where her step-aunt, Ioveta of Bethany, was abbess.
Ioveta and Sibylla supported Queen Melisende and held some influence over the church, and supported the election of Amalric of Nesle as Latin Patriarch of Jerusalem over a number of other candidates.
Sibylla died in Bethany in 1165.
Baldwin V, Count of Flanders
Baldwin V of Flanders( c. 1012 – 1 September 1067) was Count of Flanders from 1035 until his death.
He was the son of Baldwin IV, Count of Flanders, who died in 1035.
Arnulf I, Count of Flanders
Arnulf of Flanders( c. 890 – 27 March 965), called the Great, was the first Count of Flanders.
Serena Armstrong-Jones, Countess of Snowdon
Serena Alleyne Armstrong- Jones, Countess of Snowdon(" née" Stanhope; born 1 March 1970) is an Anglo- Irish aristocrat and the daughter- in- law of Princess Margaret, Countess of Snowdon, and a niece- by- marriage of Queen Elizabeth II and Prince Philip, Duke of Edinburgh.
Margaret, Countess of Vertus
Margaret, Countess of Vertus( French:" Marguerite d' Orléans"; 4 December 1406 – 1466), was a French vassal, Countess of Vertus and Etampes 1420 – 1466.
She was the daughter of Louis I, Duke of Orléans, and Valentina Visconti.
Margaret I, Countess of Flanders
Margaret I of Flanders (c. 1145 - died 15 November 1194) was ruling countess of Flanders "suo jure" from 1191 to her death.
She was the daughter of Thierry, Count of Flanders, and Sibylla of Anjou, and the heiress of her childless brother, Philip of Flanders.
Gertrude of Saxony
Gertrude of Saxony (1030 – August 4, 1113), also known as Gertrude Billung, was a countess of Holland by marriage to Floris I, Count of Holland, and countess of Flanders by marriage to Robert I, Count of Flanders.
She was regent of Holland in 1061-1067 during the minority of her son Dirk V, and regent of Flanders during the absence of her spouse in 1086-1093.
Margaret III, Countess of Flanders
Margaret III( 13 April 1350 – 16/21 March 1405) was the last Countess of Flanders of the House of Dampierre, as well as Countess of Artois and Countess of Burgundy( as Margaret II).
She was the only surviving child and heir of Louis II, Count of Flanders( 1346 – 1384) and Margaret of Brabant.
Richilde, Countess of Hainaut
Richilde, Countess of Mons and Hainaut( – 15 March 1086), was a ruling countess of Hainaut from c. 1050 until 1076, in co-regency with her husband Baldwin VI, Count of Flanders and son Baldwin II, Count of Hainaut.
She was also countess consort of Flanders by marriage to Baldwin VI, Count of Flanders.
She served as regent of Flanders during the minority of her son Arnulf III, Count of Flanders in 1070- 1071.
Margaret I, Countess of Burgundy
Margaret I( 1310 – 9 May 1382), was a ruling Countess Palatine of Burgundy and Artois from 1361 and 1382.
She was also countess of Flanders, Nevers and Rethel by marriage to Louis I, Count of Flanders, and regent of Flanders during the minority of her son Louis II, Count of Flanders in 1346.

Question: Where did Margaret I, Countess Of Flanders's mother die?
Answer: Bethany