Detailed Instructions: In this task you will be given an answer to a question. You need to generate a question. The answer given should be a correct answer for the generated question.
Q: Madison Nicole Ziegler (born September 30, 2002), better known as Maddie Ziegler, is an American dancer, actress and model. She first became known for appearing in Lifetime's reality show Dance Moms from 2011 (at age 8) until 2016. From 2014 to 2016, she gained wider fame for starring in five music videos by Sia, including 'Chandelier' and 'Elastic Heart', which cumulatively have attracted more than 3.4 billion views on YouTube. Ziegler has appeared in films, television and concerts, and has modeled on magazine covers and in advertisements for Capezio, Ralph Lauren and Target, among other brands. She was included by Time magazine on its list of the '30 most influential teens' in each of 2015 and 2016.
A:
how old is the girl in sia music video