We have her as a daughter of John le Stran IV and Joan de Somery. Cawley says that couple had 1 child, John V (not the guitar player): https://fmg.ac/Projects/MedLands/ENGLISHNOBILITYMEDIEVAL3P-S.htm#Jo....
The Peerage.com tends to agree: http://www.thepeerage.com/p56833.htm#i568321.
There are no sources saying that she was from that union, other than internet family genealogy sites.
Bartrum adds her as a note in his Marchudd 17 page: https://www.geni.com/documents/view?doc_id=6000000173393022889. If she was the mother of Sir Gruffudd Llwyd she would date to c. 1245. If she was a later wife, she could date to c. 1230. As she was added in, she does not appear in Bartrum's indexes, and the only source he provides is in the note, i.e. "see [undecipherable] letter of May 1986." This is in ink. Below that in pencil he has a note that appears to say that R.W. Llwyd suggests that the John le Strange in question is John III. He then adds that "As a widow Tregozznedd (as it seems to say) was settled on her till her death." John III was supposedly married to Lucy Tregoz. But Cawley and Peerage.com are silent on this issue.
The John le Strange(s) are often conflated and dates are hard to lock down. At any rate, even if a child of John IV, I don't think she was a daughter of Joan de Somery. And Bartrum's little blurb that seems to say she inherited some Tregoz land would argue for her to be a daughter of John III. I would argue that she at least be disconnected from Joan, at the least. In my own charting I will be moving her as being a daughter of John III and Lucy de Tregoz.
Thoughts??
