The Poyntz family are definitely a fractious lot. Somewhere you should have seen a family where one son left Winchester School to attend the English College in Rome when one of his sisters was married to the half-brother of Lady Jane Grey on the other side of the religious divide. Gwentilian Strandling was one of Elizabeth Woodville's Ladies in Waiting.Margaret must have been born before Elizabeth became Queen , so Gwentilan spent some of her time at Court. Anthony Woodville would only have been allowed to marry with the King's permission as a senior courtier, and for some reason (?avarice)he married twice to rich widows considerably older than himself and not of child bearing age. I suspect that reading around the later Wars of the Roses,Edward IV ,Richard III and the Princes in the Tower might throw some light on her world.