In the south of France, an English member of the family (5)
I believe the answer is:
niece
'member of the family' is the definition.
(I've seen this in another clue)
'in the south of france an english' is the wordplay.
'in the' means one lot of letters goes inside another.
'south of france' becomes 'nec' (I can't justify this - if you can you should believe this answer much more).
'an' becomes 'i' (Roman numeral for one).
'english' becomes 'E' (abbreviation).
'nec' going around 'i' is 'niec'.
'niec'+'e'='NIECE'
Can you help me to learn more?
(Other definitions for niece that I've seen before include "Preparation for curdling milk" , "Daughter of a sibling" , "Criminal" , "Family girl" , "Brother's daughter" .)