She also grows beautiful on water (4)
I believe the answer is:
lily
'she' is the definition.
I cannot understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for lily that I've seen before include "Flower -- girl" , "Plant like an amaryllis" , "Plant with large trumpet-shaped flowers" , "Fleur-de-lis" , "Flower of purity" .)