Leila did not say a thing with Harvey's plan. He is her chosen Champion, so she trusts his choices. And even if it turns out bad, she is on his back to clean up his messes.
And besides she knew how much Harvey values Khelly. He will never do anything that may harm her. This is his sincerity to his people.
Harvey's plan was simple. From her information about the Sand Burrowing Beast, the green eyed boy thought of using one of them as a bait to lure the adult beasts into the surface. When one of the beasts shows up, they will deal with it the fastest they could. Then they would proceed to kill the other adult.
As for the newly hatched beasts, they will leave them be. In the first place the beast of this kind is often not the most friendly to their children. Leila just thought that them killing their parents was the cubs' luck. If not, from four cubs, there might be only one living to adulthood. And if they turn out a little more lucky, two can survive.
