About ten minutes later, they had it down perfectly.
First they would wish that their parents wouldn't think their absence until eight that evening was unusual. Then they would wish that for the duration of their following wish they could communicate with eachother without speaking. Finally, they would each wish that until eight that night they would turn into a random animal, while retaining their current intellect, that could survive in their current environment. They would make the last wish individually, both because "we" was an ambigous statement that the stone might interpret poorly, and because they'd decided they wanted to transform into two different animals.
Unfortunately for both of them, their careful planning was made irrelevant by the weakened stone. There was no telling which part of each wish it would manage to grant, or how well it would manage what it [i]did[/i] grant.
