Rylee Arnold isn't the first family member - let alone sibling - of a Dancing With the Stars pro or contestant to enter the ballroom. Julianne Hough was the first dancer to face off against her brother, Derek Hough, on the ABC competition series. After Julianne got her start on the series in season 4 in 2007, she was joined by Derek the following season. Much like Derek and Julianne, Maksim Chmerkovskiy - who made his DWTS debut in season 2 - was later joined by his younger brother, Val Chmerkovskiy, as a pro in season 13.