She has many an alternative choice (6)
I believe the answer is:
mother
'she' is the definition.
Both the answer and definition are singular nouns.
Perhaps they are linked in a way I don't understand?
'many an alternative choice' is the wordplay.
'many' becomes 'M' (Roman numeral for a thousand).
'an alternative choice' becomes 'other' (I've seen this in another clue).
'm'+'other'='MOTHER'
'has' is the link.
Can you help me to learn more?
(Other definitions for mother that I've seen before include "Be overprotective" , "Nature so-called" , "Female parent" , "- - 7 across, pantomime" , "Parent to her Tom, oddly" .)