As soon as i saw here, I knew that i had met her _____.
As soon as i saw here, I knew that i had met her _____.
Explanation
As soon as I saw her, I knew I had met her before.
جیسے ہی میں نے اسے دیکھا، میں جانتا تھا کہ میں اس سے پہلے مل چکا ہوں
"Before" is used to indicate a prior encounter or experience with someone.