Oh SirFurry, I appreciated these videos VERY much...her story, her bravery along with the death of her two older sons. And, that her little boy Lord Rhys became so much a part of Welsh history.
I notice that the narrator seems to mispronounce her name? He calls her, sounds like "Gwentlian"...? However, looking at these, YouTube led me to another that I found very moving, it is the story of Llywellyn (sp?) who was killed in 1282, more than a century later. And he is known as the last Prince of Wales by Welsh patriots now, to differentiate his authenticity from the modern title.
And this video does pronounce his name beginning with the 'kitty-hissing" sound that Tink and I learned when you were giving us lessons in the Welsh language! 
Anyway, if you do watch this, be aware that its creator mentions he is not certain of the history, lost now over the centuries, but has reconstructed what he feels is very likely to have taken place in the pursuit and killing of the last Prince of Wales.
Also, Llywellyn's baby daughter was sent to spend her life in a monastery so she could never have children and thus bring an end to any possibility of continuing his lineage; and indeed she died there at the age of 55. But of interest, after seeing your videos, from the pronunciation of her name, I think the baby daughter's name was Gwenllian! ...and, this video pronounces her name with that kitty-hiss sound...oh, and I forgot me mention also, I think that the modern name Llewellyn means lion, do you know for certain? N'kay here you go, it's fascinating too...