Imagine what would have happened if Anne of Cleves, Katherine Howard or Catherine Parr had given Henry another child. How different would history be?
If another son had been born he probably would have been called Henry, or perhaps Thomas if Katherine Howard was his mother. If Anne of Cleves was his mother, he would have been born in 1540, and would have been seven when the King died (assuming everything happened as it really did). Thus he would have been 13 when Edward VI died. He then would have become King. Would he have been Protestant, or Catholic?
If the son was Katherine Howard's, and was born in 1541, he surely would have been brought up a Catholic, in the tradition of the Howards. However, if Katherine did what she did in reality and had an affair and was exevuted, would Henry have excluded his son from the succession in his will, or let him follow Elizabeth? Who knows?
Catherine Parr's son (born 1544, let us say) would certainly have been brought up Protestant. Henry certainly would have had no inhibitions about putting him directly behind Edward in the succession.
Now, if Anne of Cleve's gave Henry a daughter in 1540 (she would probably have been called Anne, Margaret or Katherine) Henry would most likely have placed in fourth in the succession, after Elizabeth (of course, if Anne had given him a child, he would not have divorced her). Unless, perhaps, he regarded Anne's child as his only LEGITIMATE daughter and put her ahead of both Elizabeth and Mary. She would have been 18 when Mary I died.
If the daughter was Katherine's, I think she would probably have been brought up Catholic. If Henry still divorced Katherine, she would likely have been placed fourth in the succession, behind Elizabeth (after all, he still reinstated Elizabeth and Mary).
Catherine Parr's daughter would have been Protestant, and still only 14 when Mary I died.
What do you all think?