Hardy girl takes a long time to find password (7)
I believe the answer is:
tessera
'password' is the definition.
(I've seen this before)
'hardy girl takes a long time' is the wordplay.
'hardy girl' becomes 'tess' (**).
'takes' is a charade indicator (letters next to each other).
'a long time' becomes 'era' (I've seen this before).
'tess'+'era'='TESSERA'
'to find' is the link.
(Other definitions for tessera that I've seen before include "Small mosaic piece" , "Small stone for mosaics" , "Small square tile used in mosaics" , "Bit of mosaic" , "Mosaic stone" .)