Girl found a ship in position (6)
I believe the answer is:
lassie
'girl found' is the definition.
(I've seen this before)
'a ship in position' is the wordplay.
'ship' becomes 'ss'.
'in' indicates putting letters inside.
'position' becomes 'lie' (lie is a kind of position**).
'a'+'ss'='ass'
'ass' placed inside 'lie' is 'LASSIE'.
(Other definitions for lassie that I've seen before include "Scots girl - film dog" , "Scottish girl - canine movie star" , "Young Scottish girl or Hollywood lost dog" , "girl found" , "Film and TV dog" .)