The girl from Redstone (4)
I believe the answer is:
ruby
'the girl' is the definition.
(girl's name)
'from redstone' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'by' (by can mean from a particular person) and 'by' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for ruby that I've seen before include "Gemstone comprising mainly aluminium oxide" , "A red jewel" , "Completely" , "Gemstone - shade of red" , "Stony girl" .)