It shows what a girl can do (7)
I believe the answer is:
sampler
'can do' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'it shows what a girl' is the wordplay.
I cannot really understand how this works, but
'it' could be 'sa' (old-fashioned abbreviation for sex appeal) and 'sa' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for sampler that I've seen before include "specimen collection" , "Taster - piece of embroidery" , "Collection of representative items" , "recording of representative items" , "Piece of embroidery showing skilled needlework" .)