Nanny's gold shoes, perhaps (2,4)
I believe the answer is:
au pair
'nanny's' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'gold shoes perhaps' is the wordplay.
'gold' becomes 'au' (Au is the chemical symbol for gold).
'shoes perhaps' becomes 'pair' (I am not sure about this - if you are sure you should believe this answer much more).
'au'+'pair'='AU PAIR'
Can you help me to learn more?
(Other definitions for au pair that I've seen before include "One helping with childcare" , "Foreign helper for room and board" , "Young foreign person offering domestic help in exchange for lodgings" , "Live-in helper from overseas for board and lodging" , "Suddenly lose one's self-control" .)