How old is Kara supposed to be on Smallville?

Answer 1

Kara was 16 when she left Krypton, at the same time as baby Clark left. Her ship crashed undetected, so she probably arrived during the meteor shower. It took baby Clark around 3 years to arrive at Earth so Kara was around 19 when she arrived. However, she was then stuck in suspended animation for a further 18 years, but did not age. Depending on whether you want how long she has lived, which would be 37 years, or how old she has aged, which is 19 years. Hope that helps!