A person of exceptional courage saving small girl (6)
I believe the answer is:
alison
'girl' is the definition.
'a person of exceptional courage saving small' is the wordplay.
'person of exceptional courage' becomes 'lion' (I can't explain this - if you can you should believe this answer much more).
'saving' means one lot of letters goes inside another.
'small' becomes 's' (abbreviation - e.g. clothes size).
'lion' enclosing 's' is 'lison'.
'a'+'lison'='ALISON'
Can you help me to learn more?
(Other definitions for alison that I've seen before include "Girl" , "woman" , "Girl's name" , "female" , "lady" .)