Tempers shown by a girl at a phoney sale (7)
I believe the answer is:
anneals
'tempers' is the definition.
('anneal' can be a synonym of 'temper')
'a girl at a phoney sale' is the wordplay.
'a girl' becomes 'ann' (woman's name).
'at' means one lot of letters go next to another.
'a phoney' indicates anagramming the letters.
'sale' anagrammed gives 'eals'.
'ann'+'eals'='ANNEALS'
'shown by' is the link.
(Other definitions for anneals that I've seen before include "Heats and then slowly cools to temper" , "Makes strong" , "And leers at the English painter" .)