The inherited sources all give Nest verch Cadell -- Nest verch Cadell, {Fictitious} -- as the wife or Merfyn Frych ap Gwriad, and hence the mother of Rhodri the Great. (Private User -- you are the curator on Nest verch Cadell, so have a stake in this.)
However, Steven Mitchell Ferry and I would like to propose that we change this.
Here is my precis of the argument (we are following the argument of Darrell Wolcott: http://www.ancientwalesstudies.org/id12.html):
Nest verch Cadell does not appear in the earliest pedigrees of Rhodri Mawr (Rhodri the Great). In Harleian MS 3859 (c. 1100), Merfyn Frych is given a mother -- Esyllt verch Cynan, as we have here in Geni -- but not a wife.
She first appears as the wife of Merfyn Frych in some pedigrees in Jesus College MS 20 (C. 1275). Later, the Achau Brenhinoedd a Thywysogion Cymru (c. 1400) made her the mother of Merfyn, not his wife.
Early historians, from 1584 on down, went along with this, and called her Merfyn Frych's mother.
J.E. Lloyd (c 1900), taking into account the early Harleian MS cited above, took her out of the place of mother, since the earliest of the surviving MSS had already given Merfyn a mother, and put her into the position of wife.
Wolcott doesn't think she existed at all.
So the question would be, why would she be made up, and what is the point of all this? And the answer, according to Wolcott, is that though Powys didn't get incorporated into Gwynedd until the late 11th century, when the sons of Cynfyn ap Gwerystan took it over, the claim was that Gwynedd had actually taken over Powys in the 9th century, and that somehow Rhodri Mawr was connected with all of this. That Powys had come to him through his mother. Nest verch Cadell.
As it happens, the mother of the two brothers who took over Powys was also called Nest verch Cadell, though of course she lived centuries later.
He believes that her name was taken and slotted in as Rhodri's mother as part of the propaganda concerning Gwynedd being a major force and Powys not being one at all.
So the first suggestion here is that we take out Nest verch Cadell as mother of Rhodri, and explain, in curators' notes and the Overview, what the problem is, that being that the earliest MS has no mention of her and that she seems to have been shoehorned into the pedigree later in order to bolster a certain interpretation of Welsh history.
That would leave us then with no mother for Rhodri the Great, which is sort of sad. I mean, he clearly did have one, but it's not at all clear (to some of us) that she was Nest verch Cadell.
Wolcott believes that she was Nest verch Cynan ap Brochwel, who was the daughter of the king of Meirionydd, and would have brought that land to the family, which did indeed hold it later.
All of this is given in more detail, with notes and references, in the Wolcott link above.
For further study of What Wolcott Thinks About Rhodri Mawr and Wikipedia, you can go to http://www.ancientwalesstudies.org/id165.html
which has the delightful title of Wikipedia's Lame Biography of Rhodri Mawr.
It gives more overview to the problems of Rhodri Mawr's inherited history.
So!
What say you all?