Cannabis would be too much for her (4)
I believe the answer is:
anna
'her' is the definition.
(I've seen this before)
'cannabis would be too much' is the wordplay.
'be too much' indicates a hidden word (the clue hides the answer plus unneeded letters).
'ANNA' is hidden in the letters of 'cannabis would'.
'for' acts as a link.
(Other definitions for anna that I've seen before include "- - Ford (TV)" , "Unit of length" , "Book by Tolstoy" , "and eleven, twenty four across heroine" , "Dame -- Neagle" .)