She's sure not right! (3)
I believe the answer is:
sue
'she's' is the definition.
'sure not right' is the wordplay.
'not' is a deletion indicator.
'right' becomes 'r' (common abbreviation).
'sure' with 'r' taken out is 'SUE'.
(Other definitions for sue that I've seen before include "Take legal case against" , "Proceed legally against (someone)" , "- - Barker, 19 star" , "Prosecute at law" , "Legally challenge" .)