My custom sovereign married Rilis, a female that could apparently kick almost anyone's rearend as she had something like 18 strength, 15 dex, 15 constitution. My king was about 13, 13, 12. We had all daughters, lucky for her the Henry the VIII mod isn't in! 
Anyway, all the girls grow up and have pitiful stats including 1's and 2's and none had much of anything worth saying "Oh, but she has high intelligence or wisdom" in fact, they are worse than any champion I have seen.
I could see one or two, but four!?
Also it seems kids are capped at 4, is that intentional?