Two girls are the making of another (8)
I believe the answer is:
rosemary
'the making of another' is the definition.
I can't tell whether this definition defines the answer.
'two girls' is the wordplay.
'two girls' can mean two replacements for 'girl'.
'girl' becomes 'rose' ().
'girl' becomes 'Mary' (girl's name).
'rose'+'mary'='ROSEMARY'
'are' acts as a link.
Can you help me to learn more?
(Other definitions for rosemary that I've seen before include "such seasons" , "Plant" , "Aromatic shrub" , "Herb - girl's name" , "Evergreen flowering shrub - girl's name" .)