Girl shows good sense (8)
I believe the answer is:
prudence
This might be a double definition.
'girl' is the first definition.
'good sense' is the second definition.
'prudence' can be an answer for 'sense' (I have seen 'Common sense ' mean 'prudence' so perhaps 'sense' could also mean 'prudence'). I'm not certain of the 'good' bit.
'shows' acts as a link.
Can you help me to learn more?
(Other definitions for prudence that I've seen before include "Caution or shrewdness" , "good management" , "Discretion, caution" , "Care and thought for the future" , "showing caution" .)