The tragic fate of the Tudor boys

 The tragic fate of the Tudor boys.

Henry VIII had numerous sons, but only two survived, Edward VI and Fitzroy . They both died in their teens. His daughters, Mary and Elizabeth lived relatively healthy and long lives.

Henry's sisters had similar situations regarding their sons.

The only two boys of the younger sister, Mary, fathered by Charles Brandon, both named Henry, both died young. Her daughters, however, Eleonor and Frances Gray, had no major problems.

Margaret Tudor, Henry's older sister, had also numerous sons, but only one survived to adulthood, James V who died at 30 years old. Her daughter, on the other hand Margaret Douglas, lived until her 60s .

And all of the above, while mortality in infancy was similar to boys and girls.

And I can't help but wonder...

What was it about the Tudor daughters that allowed them to live longer, more robust lives in comparison to their brothers?