Copper with a heart of gold, said head girl (5)
I believe the answer is:
doris
'girl' is the definition.
(I've seen this before)
'copper with a heart of gold said head' is the wordplay.
'copper' becomes 'doi' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'with' means one lot of letters goes inside another.
'a heart' indicates the central letters.
'of gold' becomes 'auric' (auric means relating to gold).
'head' indicates taking the first letters.
The middle of 'auric' is 'r'.
The first letter of 'said' is 's'.
'doi' placed around 'r' is 'dori'.
'dori'+'s'='DORIS'
Can you help me to learn more?
(Other definitions for doris that I've seen before include "In Greek myth, wife of sea-god Nereus" , "Girl" , "Woman" , "Female name" , "-- Day, actress" .)