Island girl (4)
I believe the answer is:
iona
This clue is a double definition.
'island' is the first definition.
(I've seen this before)
'girl' is the second definition.
(Other definitions for iona that I've seen before include "Scottish island noted for St Columba" , "Scottish island of ancient saints" , "one in Inner Hebrides" , "part of Scotland" , "Hebridean island famed for St Columba" .)