An infant prodigy, which is hardly surprising (6,6)
I believe the answer is:
little wonder
'is hardly surprising' is the definition.
I don't know anything about this answer so I cannot tell whether it can be defined by this definition.
'an infant prodigy' is the wordplay.
'an infant' becomes 'little' (I can't explain this - if you can you should give a lot more credence to this answer).
'prodigy' becomes 'wonder' (I've seen this in another clue).
'little'+'wonder'='LITTLE WONDER'
'which' acts as a link.
Can you help me to learn more?
(Another definition for little wonder that I've seen is " It's not surprising".)