Fe26=Fe25 William de Ferrers

    William (Walkeline) de Ferrers (Fe26)  was the son of  Robert de Ferrers (Fe27) and Margaret Peverel (1114? - 1155?) daughter of William Peverel de Nottingham and Avice de Lancaster (Nottinghams. 1092? - 1149+)
    Born:
    Married: 1st Sibyl de Braose (1148? - 1228?)
    2nd Alice Leche
    Died: 
    and had issue:
    (Fe25=Fe24) Petronella de Ferrers, married Henry de Stafford and had Robert de Stafford.
    (Fe25-2) Millicent (Isabel?) de Ferrers, married Sir Roger de Mortimer and had Joane (Isabel) de Mortimer.
    (Fe25) William de Ferrers , 4th Earl of Derby
    (Fe25-4) Agatha de Ferrers associated with King John I and had Joan of North Wales, married Hugh de Mortimer, Lord of Chelmarch
     
    Source:

    http://freepages.genealogy.rootsweb.com/~jamesdow/s092/f502189.htm