Meaning of '쎄다'?
For a subtitle originally saying '너무 소녀가 쎄지 않아요?' the translation is given as 'Isn't it too much for this to be a girl?'. I would translate it as 'Isn't this girl too strong (to be a girl)?', with 쎄지 being a different spelling of 세지 (from 세다).
Is this right or is the original translation more accurate? Thank you :3

Question

Meaning of '쎄다'?
For a subtitle originally saying '너무 소녀가 쎄지 않아요?' the translation is given as 'Isn't it too much for this to be a girl?'. I would translate it as 'Isn't this girl too strong (to be a girl)?', with 쎄지 being a different spelling of 세지 (from 세다). 
Is this right or is the original translation more accurate? Thank you :3

Answer

쎄다 is a dialect of 세다(to be strong)
너무 소녀가 쎄지 않아요?
I would translate it as 
Isn't she too strong/powerful for a girl?