Reese Witherspoon is one of those Hollywood celebrities who's seen as the "relatable" one and her adorable social media posts are proof of that.MORE: Reese Witherspoon shares rare family photos with lookalike mom Betty to mark special celebrationThe actress shared a rare throwback picture featuring both of her oldest children, son Deacon Phillippe, 17, and daughter Ava Phillippe, 21, as they all acted their silliest for the camera.WATCH: Reese Witherspoon's throwback marks big milestoneStanding