James is forced back to Scotland and Margaret might give him another 3/4 children, and let's say 2 of them survive. Already it's been suggested that Arthur Stewart survives, so let's give him 2 younger daughters, named Margaret and Elizabeth (1516 and 1519).
James IV of Scotland (b.1473: d.1524) m. Margaret Tudor (b.1489: d.1541) (a)
1a) James Stuart, Duke of Rothesay (b.1507: d.1508)
2a) Stillborn Girl (c.1508)
3a) Arthur I of Scotland (b.1509) m. Renee of France (b.1510) (a)
1a) Margaret Stewart (b.1530)
2a) James Stewart, Duke of Rothesay (b.1532)
3a) Stillborn Boy (c.1535)
4a) Alexander Stewart (b.1537: d.1538)
4a) James Stewart, Duke of Ross (b.1512: d.1549) m. Isabella of Navarre (b.1512: d.1555) (a)
1a) Mary Stewart, Duchess of Ross (b.1531)
2a) Stillborn Girl (c.1533)
3a) James Stewart (b.1535: d.1541)
4a) Margaret Stewart (b.1538: d.1540)
5a) Stillborn Boy (c.1541)
5a) Stillborn Girl (c.1512)
6a) Alexander Stewart (b.1515: d.1515)
7a) Margaret Stewart (b.1516: d.1540) m. William la Marck, Duke of Jülich-Cleves-Berg (b.1516) (a)
1a) Marie Elisabeth of Cleves (b.1534)
2a) William of Cleves (b.1535)
3a) John of Cleves (b.1536)
4a) Charles of Cleves (b.1537: d.1539)
5a) Eleanor of Cleves (b.1539)
6a) Magdalena of Cleves (b.1540)
8a) Stillborn Boy (c.1517)
9a) Elizabeth Stewart (b.1519) m. Henry II of France (b.1519) (a)
1a) Margaret de Valois (b.1540)
2a) Elisabeth de Valois (b.1542: d.1543)
3a) Claude de Valois (b.1543)
4a) Francis de Valois, Dauphin of France (b.1544)
5a) Stillborn Boy (c.1545)
6a) Madeline de Valois (b.1547)
7a) Henri de Valois, Duke of Orleans (b.1550)
8a) Stillborn Boy (c.1551)
9a) Joan de Valois (b.1553)
10a) Charles de Valois, Duke of Anjou (b.1555)
10a) Alexander Stewart (b.1521: d.1521)