Where Dill is in her element (9)

I believe the answer is:

herbarium

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'where dill is' is the definition.
The definition suggests a singular noun which matches the answer.

'her element' is the wordplay.
'element' becomes 'barium' (barium is a kind of element).
'her'+'barium'='HERBARIUM'

'in' acts as a link.

Can you help me to learn more?

(Other definitions for herbarium that I've seen before include "Plant room" , "Where Rosemary, for one, is" , "Flora preserved" .)

I've seen this clue in The Independent.

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