Weir says she died at Peel Castle, Isle of Man. She was convicted of practising whichcraft upon Henry VI. The Complete Peerage agrees.
She may have born Humphrey two children before they married, but there are no clear details.
Previously I showed her dying 7 Jul 1452 at Beaumaris Castle. http://www.hull.ac.uk/php/cssbct/cgi-bin/gedlkup.php/n=royal?royal01598
[S36] Brian Tompsett, Dept of Computer Science, University of Hull, England(B.C.Tompsett@dcs.hull.ac.uk), Directory of Royal Genealogical Data, (This work is Copyright b 1994-2002 Brian C Tompsett).