Ideally your wife should be self banning, James but maybe at this point, she is not able to do that.
I think 99% of people here will advise you not to get involved, but, personally, I would have been VERY grateful if my husband had taken that step. It would have saved me lots of grief, stress, and thousands of euro! I would see it as intervention. CGs sometimes need others to move in and help in the same way you would take the victim of a car accident to a hospital.
I know of a woman who’s husband had her banned. She never darkened the door of those casinos again and it made her realize she was becoming infamous! The security guy raised his voice and said “OUT!” the first time she entered and with all the customers turning their heads to look at her it sure made her leave fast!
It only took one visit to get her to stop…..
Getting your wife to join GT, as Velvet suggested would be a very positive move.