On 30 Mar 1231 [her future husband] Richard of Cornwall 1st Earl Cornwall (age 22) and Isabel Marshal Countess Cornwall, Gloucester and Hertford 1200-1240 (age 30) were married at Fawley, Lambourn. She by marriage Countess Cornwall. She the daughter of William Marshal 1st Earl Pembroke and Isabel Clare Countess Pembroke. He the son of King John "Lackland" of England and Isabella of Angoulême Queen Consort England (age 43).
On 23 Nov 1243 [her future husband] Richard of Cornwall 1st Earl Cornwall (age 34) and Sanchia Provence Queen Consort Germany 1228-1261 (age 15) were married at Westminster Abbey [Map]. She by marriage Countess Cornwall. She the daughter of Raymond Berenguer Provence IV Count Provence 1198-1245 (age 45) and Beatrice Savoy Countess Provence 1198-1267 (age 45). He the son of King John "Lackland" of England and Isabella of Angoulême Queen Consort England (age 55). They were fourth cousins.
On 16 Jun 1269 Richard of Cornwall 1st Earl Cornwall (age 60) and Beatrice Falkenburg Countess Cornwall were married at Kaiserslautern. She by marriage Countess Cornwall. He the son of King John "Lackland" of England and Isabella of Angoulême Queen Consort England.
On 02 Apr 1272 [her husband] Richard of Cornwall 1st Earl Cornwall (age 63) died at Berkhamsted Castle, Hertfordshire [Map]. He was buried at Hailes Abbey [Map]. His son [her step-son] Edmund "Almain" 2nd Earl Cornwall (age 22) succeeded 2nd Earl Cornwall.