Turning fifteen, vacant daughter is not the same (9)
I believe the answer is:
different
'not the same' is the definition.
(I've seen this before)
'turning fifteen vacant daughter' is the wordplay.
'turning' indicates an anagram.
'vacant' suggests removing the centre (a vacant or emptied out form of the word).
'daughter' with its centre taken out is 'dr'.
'fifteen'+'dr'='fifteendr'
'fifteendr' with letters rearranged gives 'DIFFERENT'.
'is' acts as a link.
(Other definitions for different that I've seen before include "Distinct, separate" , "Dissimilar, unlike" , "Unusual" , "Otherwise" .)