A girl to put your shirt on? (3)
I believe the answer is:
bet
'a girl' is the definition.
'your shirt on?' is the wordplay.
'your' becomes 'be' (I can't explain this - if you can you should give a lot more credence to this answer).
'shirt' becomes 't' (as in a T-shirt).
'on?' is a charade indicator (letters next to each other).
'be'+'t'='BET'
'to put' is the link.
Can you help me to learn more?
(Other definitions for bet that I've seen before include "Wager, gamble" , "Wager, or the sum waged" , "Wager, back" , "Speculation" , "Money risked on a gamble" .)