Carve two little heads in alabaster? (7)
I believe the answer is:
whittle
'carve' is the definition.
(thesaurus)
'two little heads in alabaster?' is the wordplay.
'heads' says to take the initial letters.
'in' is an insertion indicator.
'alabaster?' becomes 'white' (alabaster is a kind of white).
The first letters of 'two little' is 'tl'.
'tl' placed inside 'white' is 'WHITTLE'.
(Other definitions for whittle that I've seen before include "Pare thin shavings" , "Trim wood by cutting thin slices from its surface" , "Jets designer" , "Carve (wood) with small slices" , "cut with a knife" .)