On Monday, Sarah styled the beautiful Hailee Steinfeld for the Z100 Jingle Ball lineup announcement at the Macy's in New York City. Sarah gave Hailee a beautiful, sleek look with her ceramic styling iron. Along side Nick Jonas, Hailee announced the lineup for Jingle Ball. In addition to many major names, Hailee will also be performing at the concert. Jingle Ball is on December 11, where Hailee will also be celebrating her 19th birthday. What a fun way to celebrate!