Ok hasn't anyone thought up the fact that this idea of love between Elizabeth and Richard makes them both look bad? Not only does it trump on history of Elizabeth's actual marriage being a good one but it makes Richard and Elizabeth willing participants in incest of one of the worst degrees. Why would any Richard defender want to use such a thing to try and make him look better?
Ok.
This is based on the letter "found" by Buck and it is no longer extant but there is evidence to suggest that it had been tampered with not least by Buck's nephew. ( sorry, I cannot find the source for this at the moment in my massive pile of "stuff". :-) ).
The letter suggests that it was very much Elizabeth who was "chasing" Richard and not vice-versa, to wit - she asks Norfolk to intercede, i.e. put in a good word for her.
Elizabeth would bring no suitable dowry to the marriage and there would be no profitable foreign alliance.
The sheer absurdity of marriage plans with a niece declared illegitimate would make a travesty of Titulus Regis.
Denial by Richard of any marriage plans ( which is preserved verbatim in the records of the Mercers.)
At this time,Richard was planning a marriage with Joanna of Portugal ( note she was of Lancastrian "blood" ) with Elizabeth to wed Manuel of Portugal who was cousin to Joanna.