Pretty shrewd (4)
I believe the answer is:
cute
I believe this is a double definition.
'pretty' is the first definition.
(thesaurus)
'shrewd' is the second definition.
(I've seen this before)
(Other definitions for cute that I've seen before include "Attractive and quaint (4" , "Quaintly pleasing" , "Astute - lovely" , "winning" , "Sweet, attractive" .)