If the game is really that important to you, I suggest making a backup of your game. That way, if the adoption event doesn't come, you can just replay the game from this moment on, which means a second chance to get the adoption event. You can keep restarting the backed-up game, giving yourself chance after chance to get the adoption event.

To backup the game, just figure out which file belongs to it, and zip it up or just copy it over to a safe place. I think there's a sticky post somewhere that tells more about making backups.