Wind up? Peg out little one (6)
I believe the answer is:
kiddie
'little one' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.
'wind up? peg out' is the wordplay.
'wind up?' becomes 'kid' (I can't justify this - if you can you should believe this answer much more).
'peg out' becomes 'die'.
'kid'+'die'='KIDDIE'
Can you help me to learn more?
(Other definitions for kiddie that I've seen before include "youngster" , "Young child (informal)" .)