Ben M. Angel's summary:

Relationships:

Parents: William de Burgh (1312 - 1333), 3rd Earl of Ulster, murdered by the Mandevilles while en route to Parliament to be made Lord Burgh.

Matilda (Maud) de Lancaster (1310-1377), Canoness of Campsey (1347-1364), Nun at Bruisyard Abbey (1364-1377)

Siblings: Only child.

Spouse: Lionel "of Antwerp" (1338-1368), Guardian of England (1345-1346), Earl of Ulster de iure uxoris (1347-1368), Duke of Clarence (1672-1368), Chief Governor of Ireland (1361-1365, 1367)

Child: 1. Philippa (1355-1378/1381) Countess of Ulster, wife of Edmund Mortimer (1352-1381), Earl of March (to 1381), Earl of Ulster, Lord of Connaught, and Lord of Clare (1368-1381), Marshal of England (to 1376), King's Lieutenant in Ireland (1379-1381)

Basic information and justifications:

Birth:17 September 1312 at Carrickfergus Castle, County Ulster, Ireland (FMG, Wikipedia, Lundy, etc.)

Death: 10 December 1363 at Dublin (Wikipedia)

Buried: Clare Priory, Clare, Suffolk, England

Occupation: 4th Countess of Ulster (6 June 1333 - 10 December, 1363; FMG, Wikipedia, Lundy, etc.), Duchess of Clarence (Plaque at Clare Priory)

Alternate names: None noted. (Was written in one source document as "Elizabetha de Borrow" but this is probably more a reflection on how her name was pronounced - much like Jedburgh in southern Scotland sounds like "Jedborrow".)

Special note: Should not be confused with Elizabeth de Burgh, wife of Richard de Richmond (different person). This Elizabeth was also never married to his brother, Elyas de Richmond, or any de Richmond for that matter, a mistake that some GEDCOMs apparently transmit - check sources, this person is pretty well documented.

http://en.wikipedia.org/wiki/Elizabeth_de_Burgh,_4th_Countess_of_Ulster

http://thepeerage.com/p10688.htm#i106872

http://www.findagrave.com/cgi-bin/fg.cgi?page=gr&GRid=16607584

http://www.mathematical.com/burghelizabeth1332.htm