The meaning: "were all thy children kind and natural" in Henry the V? (war, England)

[DraggingCanoe]

Who are the kind and natural children? What does this mean?

[Fontucky]

Original: What might’st thou do, that honor would thee do, Were all thy children kind and natural!

Modern version: There is nothing you couldn’t accomplish if all your subjects were loyal and loving!

[NJGOAT]

Originally Posted by Fontucky

Original: What might’st thou do, that honor would thee do, Were all thy children kind and natural!

Modern version: There is nothing you couldn’t accomplish if all your subjects were loyal and loving!

Bingo. You have to put it into context of what the rest of the opening chorus is talking about:

Original:

Now all the youth of England are on fire,
And silken dalliance in the wardrobe lies.
Now thrive the armorers, and honor’s thought
Reigns solely in the breast of every man.
They sell the pasture now to buy the horse,
Following the mirror of all Christian kings
With wingèd heels, as English Mercurys.
For now sits Expectation in the air
And hides a sword, from hilts unto the point,
With crowns imperial, crowns and coronets
Promised to Harry and his followers.
The French, advised by good intelligence
Of this most dreadful preparation,
Shake in their fear, and with pale policy
Seek to divert the English purposes.
O England, model to thy inward greatness,
Like little body with a mighty heart,
What might’st thou do, that honor would thee do,
Were all thy children kind and natural!
But see, thy fault France hath in thee found out,
A nest of hollow bosoms, which he fills
With treacherous crowns, and three corrupted men—
One, Richard, Earl of Cambridge, and the second,
Henry, Lord Scroop of Masham, and the third,
Sir Thomas Grey, knight, of Northumberland—
Have, for the gilt of France (Oh, guilt indeed!),
Confirmed conspiracy with fearful France,
And by their hands this grace of kings must die,
If hell and treason hold their promises,

Modern:

Now all the young men of England are inspired and have stored their party clothes in the closet. Armorers are doing great business, and all men think about is honor. People are selling off their land to buy warhorses so they can follow the exemplary king into battle as if they had winged feet, like Mercury. There’s a sense of anticipation in the air. In the minds of Harry and his followers, visions of the kingdoms, spoils, and titles to be won eclipse thoughts of actual fighting. The French, meanwhile, have been forewarned of all this preparation by their spies and tremble in fear. They seek to derail the English with cowardly tricks. Oh, England! You are physically small but inwardly great, like a mighty heart enclosed in a small body. There is nothing you couldn’t accomplish if all your subjects were loyal and loving! But, see, the king of France has detected your weak spot: a nest of faithless traitors, whose treachery he has purchased with gold. Three corrupt men—Richard, earl of Cambridge; Henry, Lord Scroop of Masham; and Sir Thomas Grey, knight, of Northumberland—have agreed to conspire with the French in exchange for money. The gracious king will die by their hands in Southampton before he sets sail for France—if Hell and treason have their way. Stick with us, ladies and gentlemen, and we’ll make a play, conquering space and time. Imagine that the traitors have been paid and made their choice. The king has left London, and the scene now

The line in particular is basically stating that if all of England's men were loyal they could accomplish anything do to their great strength, in this case win the war in France. However, because of the "nest of traitors" that have been bought with French gold, the outcome of the war is not certain and the king's life is on the line.

If we needed to name who the "children/subjects" are, we could assume that they are directly referencing the three men later named, Richard of Cambridge, Henry of Masham and Thomas Grey.