Copy one child in enamel work (9)
I believe the answer is:
cloisonne
'enamel work' is the definition.
(I've seen this before)
'copy one child in' is the wordplay.
'copy' becomes 'clone' (cloning is a kind of copying).
'one' becomes 'i' (Roman numeral).
'child' becomes 'son' (male child).
'in' indicates putting letters inside.
'i'+'son'='ison'
'clone' enclosing 'ison' is 'CLOISONNE'.
(Other definitions for cloisonne that I've seen before include "enamelware" , "Enamel work" , "Panelled enamelwork" , "Sort of design" .)