It shows she's married to a fish! (7)
I believe the answer is:
herring
'a fish' is the definition.
(herring is a type of fish)
'it shows she's married to' is the wordplay.
'it shows' becomes 'ring' (I can't justify this - if you can you should believe this answer much more).
'she' becomes 'her' (I've seen this in other clues).
'married to' is a charade indicator (letters next to each other).
'ring' after 'her' is 'HERRING'.
Can you help me to learn more?
(Other definitions for herring that I've seen before include "Fish of northern waters, can be salted or pickled" , "Fatty fish" , "Fish, often kippered" , "It's certainly fishy!" , "one could be soused" .)