John Ravilous ascribed her parentage as follows on 23rd April 2004:

"Dear Richard,

     Indeed, your post found it's way to the mark.

     The problem lies in the phrasing of the KEI citation, which on
the surface would seem to imply a 1295 marriage date.  In fact,
Beatrice Foliot is correctly placed as the daughter of the earlier
Jordan Foliot (d. bef Mar 1235), as I indicated.  My apologies for
perhaps not having explained this problem more thoroughly at the
time.  

     Sir Richard Foliot (d. 1299), son of the aforesaid Jordan, is
clearly identified in the IPM of Simon de Pateshull as the brother of
Beatrice Foliot, wife of Simon, and that Simon held certain lands in
Lincolnshire (including Frisby) of Sir Richard.  My notes based on
'Yorkshire Inquisitions' reflect the following, incl. the citation
from that text:

   ' IPM of Simon de Pateshulle in co. Lincs., in answer to writ of
      diem clausit extremum dated Westminster, 2 Dec 24 Edw. I (1295):
   " By the second [Lincoln] the jurors find that Simon held certain
     lands and tenements in Lincolnshire of Richard Folyot, as those
     which Jordan Folyot, father of Richard, gave to Simon de
     Steyngreve, grandfather of Isabel, in frank marriage with
     Beatrice his daughter." [Yorks. Inqs. III:26, note (b) ]     '

     Simon de Pateshull was married to Isabel de Stonegrave (or
Steyngrave), daughter of John de Stonegrave (d. 20 April 1295), the
son of Simon de Stonegrave and Beatrice Foliot.

     The 1295 reference date from 'Knights of Edward I', taken from an
IPM of that year, is misleading, and should not be taken to refer to
a marriage taking place in that year.

     Cheers,

                               John *

* John P. Ravilious