Information on girl in Swiss city (6)
I believe the answer is:
geneva
'swiss city' is the definition.
(I've seen this before)
'information on girl' is the wordplay.
'information' becomes 'gen' (gen is a kind of information).
'on' is a charade indicator (letters next to each other).
'girl' becomes 'eva'.
'gen'+'eva'='GENEVA'
'in' acts as a link.
(Other definitions for geneva that I've seen before include "Alpine lake" , "Swiss city, lake" , "Juniper flavoured spirit - Red Cross HQ" , "old Calvinist stronghold" , "City and lake in SW Switzerland" .)