About daughter verch Llywelyn
Documentation in *The Genealogist* (Association for the Promotion of Scholarship in Genealogy), vol. 1, no. 1 (Spring 1980), pp. 80-95.
Her mother is not given; she is presumable one of Llywelyn's children by an unknown mistress.
not found on FMG: http://fmg.ac/Projects/MedLands/WALES.htm#Llywellyndied1240B
brief web search shows no other mention of William Caentwn; there is a farm called "Caen Twn," or "Caen Dwn."
[24 Jan 2011, Janet Palo-Jackson, curator; 18 Dec 2015, Anne Brannen, curator]