Robert Irwin’s cutest dance partner yet? His 4-year-old niece Grace! As Robert Irwin dazzles audiences on Dancing with the Stars, it turns out his biggest fan (and toughest coach) might be waiting for him at home. In a heartwarming Instagram video shared over the weekend, Robert gave fans a glimpse into his off-stage training routine, featuring none other than his 4-year-old niece, Grace Warrior. Grace has won!”AdvertisementRobert, 21, is currently competing in season 34 of Dancing with the Stars with partner Witney Carson.