She gives a negative answer if upset (5)
I believe the answer is:
fiona
'she' is the definition.
'a negative answer if upset' is the wordplay.
'negative answer' becomes 'no'.
'upset' says the letters should be written in reverse.
'a'+'no'+'if'='anoif'
'anoif' back-to-front is 'FIONA'.
'gives' is the link.
(Other definitions for fiona that I've seen before include "Girl's name, meaning fair in Gaelic" , "Girl" , "Girl's name (not Flora)" .)