Girl I married over in cathedral city (5)
I believe the answer is:
emily
'girl' is the definition.
'i married over in cathedral city' is the wordplay.
'married' becomes 'm'.
'over' is a charade indicator (letters next to each other) (in a down clue, some letters go over others).
'in' is an insertion indicator.
'cathedral city' becomes 'ely' (English city with a cathedral).
'i' after 'm' is 'mi'.
'mi' placed inside 'ely' is 'EMILY'.
(Other definitions for emily that I've seen before include "Literary sister" , "One of the Bronte sisters" , "A Bronte sister" , "Woman" , "Girl" .)