Seven years before Rylee Arnold and Hailey Bills slayed the Dancing With the Stars stage, they were both junior pros on the younger iteration of the ballroom competition. In 2018, DWTS aired a junior version of the competition where a slate of child stars or kids of celebrities competed for a star-shaped mirrorball trophy. The cast included Ariana Greenblatt, Miles Brown, Mackenzie Ziegler and Olympian Sky Brown, all of whom were partnered with a preteen dancer and mentored by a DWTS professional dancer. For instance, then-pro Lindsay Arnold served as the mentor and choreog...