Have you ever looked at a movie screen and thought, "Arre, I know this face! I have seen this kid somewhere!" ? Well, get ready for a major flashback. The cute little girl who made us cry in Deiva Thirumagal  (with Vikram) and mesmerized us as the young Aishwarya Rai in Ponniyin Selvan  is all grown up. Meet Sara Arjun . She is just 20 years old, but she has been working for 15 years! Now, she is ready for her biggest Bollywood dhamaka, playing the leading lady opposite super