Margaret (Dymoke) Fitzwilliam - Who are the correct parents?

Tagging the parent sets

Sir Thomas Dymoke, King's Champion & Elizabeth Hebden

Vs Sir Thomas Dymoke, Esq. & Dame Margaret Welles

I’m not seeing how she could have been the daughter of Margaret Welles

From https://groups.google.com/forum/m/#!topic/soc.genealogy.medieval/Ql... “The Descendants of Thomas de la Haye - Part III” Discussion 2013

“.... So Complete Peerage was correct in identifying Robert Radcliffe, the second husband of Margaret Welles, as the son of Sir John Radcliffe. Given that her first marriage to Sir Thomas Dymoke occurred in 1457 and that their son and heir Robert Dymoke was born about 1461, Margaret Welles was likely herself born about 1440. ....”

Even if the birthdate for Margaret Dymoke is wrong.

Both Margarets are my 15th GGMs. The geni profile & About section do not mention a 2nd husband (Radcliffe) for Lady Margaret (de Welles). I don't see that Margaret Dymoke (Fitzwilliam) could be the daughter of Lady Margaret - there is a generation between them.
In the way these genealogical lines work, Lady Margaret's brother is my 16th GGF

Thomas Dymoke, Champion of England m. Elizabeth Hebden
Their son: Philip m. Joan Conyers/ his sister: MARGARET m. FITZWILLIAM
Philip's son Thomas Dymoke, Esq/////////////Margaret's dau. Beatrice Woodruffe
m. LADY MARGARET DE WELLES

Yes, i believe http://www.cracroftspeerage.co.uk/online/content/dymoke.htm got this particular relationship wrong. It’s generally a very good source.