Spa whence wealthy queen came, king's wife (9)
I believe the answer is:
bathsheba
'king's wife' is the definition.
(wife of King David in the Bible)
'spa whence wealthy queen came' is the wordplay.
'spa' becomes 'bath'.
'whence wealthy queen came' becomes 'Sheba' (Queen of Sheba).
'bath'+'sheba'='BATHSHEBA'
(Other definitions for bathsheba that I've seen before include "OT character" , "female partner in affair" , "David's wife" , "woman once exploited" , "biblical character" .)