Song, and in French, digested by a girl (7)
I believe the answer is:
arietta
'song' is the definition.
(arietta is a kind of song)
'french digested by a girl' is the wordplay.
'french' becomes 'et' (I can't justify this - if you can you should give a lot more credence to this answer).
'digested by' is an insertion indicator.
'girl' becomes 'Rita' (woman's name).
'a'+'rita'='arita'
'et' inserted inside 'arita' is 'ARIETTA'.
'and in' acts as a link.
Can you help me to learn more?
(Other definitions for arietta that I've seen before include "Little aria" , "Short operatic air" , "number from opera" , "Short operatic song" , "Short operatic number" .)