Kind Conservative girl (5)
I believe the answer is:
class
'kind' is the definition.
(I've seen this in another clue)
'conservative girl' is the wordplay.
'conservative' becomes 'C' (UK political abbreviation).
'girl' becomes 'lass' (lass can informally mean a girl).
'c'+'lass'='CLASS'
(Other definitions for class that I've seen before include "School form" , "High-quality" , "Category; lesson" , "Study group" , "sophistication" .)