So far every thing I have found lists her parents as "UNKNOWN"
Only WIKITREE hints as to a mother for her as follows
Judith Montanolier formerly DeMontanolier
Born [date unknown] in Normandy, , , France
Daughter of [father unknown] and Harlette (Falaise) Mortain
Died 1015 in Maidstone, Shropshire, , England
http://www.wikitree.com/wiki/DeMontanolier-1
most of the sites. lists her birth date as 1004