I have to give Gregory credit for the ending of The White Queen. All the way through the book the hint of witchcraft is maintained and comes to fruition when Elizabeth Woodville and her daughter Elizabeth curse whoever killed the Princes in the Tower. They know it is not Richard, and suspect Buckingham and the Stanleys but cannot prove it. The curse decrees that the firstborn son of the culprit shall die through the coming generations until there are only girls left....well, we know who that pinpoints as the culprit, don't we?
So Gregory has avoided angering the Ricardians, found a novel way of stating the guilty party (no pun intended) and given the reader a flavour of the unease, uncertainty and distrust of the times into the bargain.
Good for her. But I still don't care for her heroine.