Euphemia de Clavering (b. after 1265 Clavering, Essex)2,3,4,5 married Sir Randolph de Neville, 1st Lord Neville of Raby, Constable of Warkworth Castle, son of Robert de Neville and Mary FitzRanulph, before 12 March 1281.2,3,4,5
They had 5 sons (Sir Robert; Sir Ralph, 2nd Lord Neville; Sir Alexander; John; & Thomas, Archdeacon of Durham) and 4 daughters (Anastasia, wife of Sir Walter de Fauconberg; Mary; Ida; & Eupheme).2,3,4,5
Royal Ancestry by Douglas Richardson Vol. IV page 228
RANULPH (or RALPH, RANDOLPH) DE NEVILLE (also known as RANULPH FITZ ROBERT DE NEVILLE), Knt., married (2nd) MARGERY DE THWENG, daughter of John, son Marmaduke de Thweng. They had no issue.
Euphemia de Clavering died circa 1320 at Warworth, England; Buried at St. Mary's Church, Staindrop, Durham.
Father: Sir Robert FitzRoger, 5th Baron Warkworth, 1st Baron Clavering, 1st Lord FitzRoger6,3,7,5 (b. c 1247, d. b 29 Apr 1310)
Mother: Margery la Zouche6,3,7,5 b. c 1251
"Eupheme de Clavering, daughter of Robert FitzRoger, Knight, by Margery daughter of Alan la Zouche, Knight, of Ashby, married Sir Randolph (or Ralph) de Neville, 1st Lord Neville of Raby, Constable of Warkworth Castle before 12 March 18 Oct 1280/1." They had five sons, Robert, Knight, Ralph, Knight, 2nd Lord Neville, Alexander, Knight, John, Thomas, Archdeacon of Durham, and four daughters, Anastasia (wife of Walter Fauconberg, Knight), Mary Ida and Eupheme. 
Robert de "Peacock of the North" Neville (d. Jun 1319)
Anastasia de Neville (d. a 1315)
Sir Ralph de Neville, 2nd Baron Nevill of Raby, Sheriff of Hutton, Snape, Sutton in the Forest, & Wells+ [9,3,5] (b. c 1291, d. 5 Aug 1367)
Royal Ancestry 2013 D. Richardson Vol. IV p. 227-228
Magna Carta Ancestry 2011 2nd ed. Vol. III p. 241-242
↑ 1.01.11.21.3 Magna Carta Ancestry, (2nd ed, Vol. I, pp. 492). Salt Lake City, UT: N.p.;
Magna Carta Ancestry, (2nd ed, Vol. III, pp. 241). Salt Lake City, UT: N.p.
Royal Ancestry, (Vol. II, pp. 225). N.p; Royal Ancestry, (Vol. IV, pp. 226-227). N.p.
↑ 2.02.1 Royal Ancestry: A Study in Colonial and Medieval Families, (Vol IV, pp. 228)