OMG! Who scared Shahid's sister?

The young actress, who is seen shaking a leg with Shahid and co-star Alia Bhatt on the Amit Trivedi-composed track "Gulabo", was initially scared to perform with her brother, who is known for his excellent dancing skills."I was very nervous on the first day. But the atmosphere of the song was such that once the camera started rolling, I wasn't his sister, nor he was my brother. We both were playing character and what followed was pure fun, as is evident in the song."