Henry Stafford 2nd Duke of Buckingham had a son Edward Stafford 3rd Duke of Buckingham who had a son also... Henry Stafford 1st Baron Stafford... who recovered under Henry VII some of the forfeited lands of his grandfather in the OTL...
The Staffords are descended through the female line from Edward III's youngest son, which is why it is believed by half of the historians that in 1484 Buckingham's rebellion and his proclamation were made in his own name and not in Henry Tudor's. Thus a Stafford could be elected as a compromise king, supported by the nobility who hope they could rule through him.
One wonders what would become of Edward IV's daughters in this situation. IIRC Elizabeth is still in sanctuary at Westminster Abbey with her mother, so no one SHOULD be able to seize control of her person. But if one of the rivals has control of London and makes an agreement with the Queen Dowager (of Edward IV, ie Elizabeth Woodville as was) she might let her daughter out to marry them. It would be quite a coup, for John de la Pole especially since he is of age. It would be a bit less useful for Edward of Warwick, though a formal marriage could not be undone.
The other daughters I can't remember where Richard III packed them off to, probably a series of convents. They might thus be seized, or 'encouraged' to leave by ambitious nobles looking to marry them and raise a minor stake in the crown for themselves.
Best Regards
Grey Wolf