From which “mother” dispenses liquid, note, and a drug (6)
I believe the answer is:
teapot
'from which mother dispenses liquid' is the definition.
('shall I be mother?' means shall I pour the tea)
'note and a drug' is the wordplay.
'note' becomes 'te' (musical note).
'and' means one lot of letters go next to another.
'drug' becomes 'pot' (slang term for cannabis).
'te'+'a'+'pot'='TEAPOT'
(Other definitions for teapot that I've seen before include "source of refreshment" , "Spouted holder" , "Container for hot drink" , "drinks dispenser - with 5d" , "Cuppa brewer" .)