Geni is claiming it is unable to find a link between John de Welles and Cecily Plantagenet on Wikipedia.
I do not know the authority of these pages, however I would question whether any internet information is viable regarding royal lineages. I consider Wikipedia the least viable of any.
Here's the WIKIPEDIA information anyhow, which verifies a link, if you must believe Wiki: http://en.wikipedia.org/wiki/John_Welles,_1st_Viscount_Welles
WIKI: Cecily of York http://en.wikipedia.org/wiki/Cecily_of_York
http://www.tudorplace.com.ar/PLANTAGENET3.htm#Cecily%20PLANTAGENET%... Tudor Place
http://histfam.familysearch.org/getperson.php?personID=I30779&a...... FamilySearch Community Trees
http://wc.rootsweb.ancestry.com/cgi-bin/igm.cgi?op=GET&db=m...... Rootsweb
http://www.gurganus.org/surname.cfm?surname=Welles Our Family Tree: Surname Welles
http://www.bibliotecapleyades.net/sociopolitica/sociopol_garter04c.htm
LADIES OF THE GARTER
http://www.deeprootstalltrees.com/Harrington/harrington_pd/43384.htm Deep Roots and Tall Trees
http://genealogy.links.org/links-cgi/readged?/home/ben/camilla-gene...
Geni needs to be more cautious in its research in the future.
Regards.