Girl has half-hour in a state (5)
I believe the answer is:
idaho
'in a state' is the definition.
(I've seen this before)
'girl has half-hour' is the wordplay.
'girl' becomes 'ida' (**).
'has' says to put letters next to each other.
'half' suggests halving the letters.
'hour' cut in half is 'ho'.
'ida'+'ho'='IDAHO'
(Other definitions for idaho that I've seen before include "State of north-west USA" , "Another state" , "Union member?" , "My Own Private -- (1991 film)" , "US state S. of Montana" .)