POD: Henry VII had a daughter before becoming king. (Female Roland de Velville)
Catherine [1] of England (1474-1535) m. James IV of Scotland (1473-1513) [2]
1) Margaret (1490-1540) m. a) Ferdinand II of Aragon (1452-1516), b) Thomas Bellenden of Auchnoule (1485-1547)
2) James V of Scotland (1492-1550) m. Margaret of Angouleme (1492-1549)
3) Robert (1495-1561) m. Isobel Hoppar (1490-1560)
4) Henry (1497-1563) m. a) Anne de la Tour d'Auvergne (1496-1524), Janet Douglas (1498-1566) [3]
5) Mary (1500-1560) m. Henry II of Navarre (1503-1555)
6) Alexander (1504-1567) m. Margaret Erskine (1515-1572)
[1] Named after Catherine of Valois, obviously.
[2] Flodden still happens, can't see why Henry VIII having a different sister married to him changes that
[3] Obviously she's not burned ITTL