The Irish Ram
LITTLE GIRL / Ram Tough
Since you could tell the child whatever you wanted, there would be no problem.
The only problem would be that if they learned the truth, then they would know their real parents were murdered so that their land could be stolen.
In which case then the child should revenge for their parents by killing the murderers.
And that would be justice.
There was no excuse at all for Joshua to invade Jericho.
It was murder and theft.
Saul disobeyed God, and didn't kill the one whose offspring came close to wiping out the Jews in Persia. Thanks to the guts of Esther, he was finally killed.