She gets Annie no end upset! (4)
I believe the answer is:
nina
'she' is the definition.
'annie no end upset' is the wordplay.
'no end' means to remove the last letter.
'upset' indicates anagramming the letters.
'annie' with its final letter removed is 'anni'.
'anni' with letters rearranged gives 'NINA'.
'gets' acts as a link.
(Other definitions for nina that I've seen before include "One of Columbus's ships in 1492; girl's name" , "- - Simone, 1933-2003, singer" , "- Simone, US singer" , "Girl" , "Al Hirschfeld's 'hidden' daughter" .)