Girl in pool (5)
I believe the answer is:
kitty
This clue is a double definition.
'girl' is the first definition.
'pool' is the second definition.
(both can mean a shared fund)
'in' acts as a link.
(Other definitions for kitty that I've seen before include "Pool - puss" , "Perhaps a small Abyssinian" , "Communal fund" , "Pool - 4 down" , "Common pool of money" .)