Just a query - re Lowri ferch Fychan/Lowri ferch Hywel Fychan that you refer to
is she the Lowri who was the sister of Owain Glyndwr?
If so , she is an ancestor of mine. She married Robert Puleston
PS - Lowri's father was Gruffydd Fychan , I think that Fychan just means son of - i.e. in your case Hywel's father was also called Hywel
Sorry for the late reply. The two I mentioned married. Gruffudd ap Lewys father is according to Ancestry Robert Lloyd Abt. 1500 of, Cynllwyd, Llanuwchllyn, Merionethshire, Wales, D:Abt. 1605. Married Mawd ferch Dafydd, Abt. 1500 of, Y Plās Du, Llannerch Banna, Flintshire, Wales, D:abt 1568. I don't have any sisters or brothers of these in my tree.