A woman switched ledge for a flower (9)
I believe the answer is:
amaryllis
'flower' is the definition.
(I've seen this before)
'a woman switched ledge' is the wordplay.
'woman' becomes 'Mary' (woman's name).
'switched' is a reversal indicator.
'ledge' becomes 'sill' (I've seen this in another clue).
'sill' backwards is 'llis'.
'a'+'mary'+'llis'='AMARYLLIS'
'for a' is the link.
(Other definitions for amaryllis that I've seen before include "Showy bulbous plant" , "Sly alarm I turn on for the flower" , "Large-flowered bulb" , "Bulbous plant with trumpet-shaped flowers" , "belladonna lily brought this about" .)