Most senior woman swindled about Japanese currency (7)
I believe the answer is:
'most senior woman' is the definition.
(doyenne means the most respected woman in a field)
'swindled about japanese currency' is the wordplay.
'swindled' becomes 'done' (do can mean to swindle or cheat).
'about' is an insertion indicator.
'japanese currency' becomes 'yen' (the currency of Japan is the yen).
'done' placed around 'yen' is 'DOYENNE'.
(Other definitions for doyenne that I've seen before include "Senior female member of a group" , "Woman who is senior member of her profession" , "An older academic" , "Prominent female in her field" , "Respected senior woman" .)