From https://en.wikipedia.org/wiki/Elizabeth_of_Rhuddlan:
Elizabeth of Rhuddlan (7 August 1282 – 5 May 1316) was the eighth and youngest daughter of King Edward I and Queen Eleanor of Castile. Of all of her siblings, she was closest to her younger brother King Edward II, as they were only two years apart in age.
First marriage
In April 1285 there were negotiations with Floris V for Elizabeth's betrothal to his son John I, Count of Holland. The offer was accepted and John was sent to England to be educated. On 8 January 1297 Elizabeth was married to John at Ipswich. In attendance at the marriage were Elizabeth's sister Margaret, her father, Edward I of England, her brother Edward, and Humphrey de Bohun. After the wedding Elizabeth was expected to go to Holland with her husband, but did not wish to go, leaving her husband to go alone.
After some time travelling England, it was decided Elizabeth should follow her husband. Her father accompanied her, travelling through the Southern Netherlands between Antwerp, Mechelen, Leuven and Brussels, before ending up in Ghent. There they remained for a few months, spending Christmas with her two sisters Eleanor and Margaret. On 10 November 1299, John died of dysentery, though there were rumours of his murder. No children had been born from the marriage.
Second marriage
On her return trip to England, Elizabeth went through Brabant to see her sister Margaret. When she arrived in England, she met her stepmother Margaret, whom Edward had married while she was in Holland. On 14 November 1302 Elizabeth was married to Humphrey de Bohun, 4th Earl of Hereford, 3rd of Essex, also Constable of England, at Westminster Abbey.
Issue
The children of Elizabeth and Humphrey de Bohun, 4th Earl of Hereford were:
1.Hugh de Bohun (September 1303 – 1305)
2.Lady Eleanor de Bohun (17 October 1304 – 1363)
3.Humphrey de Bohun (b&d 1305) (buried with Mary or Margaret)
4.Mary or Margaret de Bohun (b&d 1305) (buried with Humphrey)
5.John de Bohun, 5th Earl of Hereford (23 November 1306 – 1335)
6.Humphrey de Bohun, 6th Earl of Hereford (6 December c. 1309 – 1361)
7.Margaret de Bohun, 2nd Countess of Devon (3 April 1311 – 1391)
8.William de Bohun, 1st Earl of Northampton (1312–1360).
9.Edward de Bohun (1312–1334), twin of William
10.Eneas de Bohun, (1314 - after 1322); he is mentioned in his father's will
11.Isabel de Bohun (b&d 5 May 1316)
Later life
During Christmas 1315, Elizabeth, who was pregnant with her eleventh child, was visited by her sister-in-law, Queen Isabella of France. This was a great honour, but the stress of it may have caused unknown health problems that later contributed to Elizabeth's death in childbirth. On 5 May 1316 she went into labour, giving birth to her daughter Isabella. Both Elizabeth and her daughter Isabella died shortly after the birth, and were buried together in Waltham Abbey.