The JW message resonates most strongly with those who are dealing with difficult situations in life. Your friend may be clinging to the org more tightly than ever, as she may feel it is a familiar path to redemption and eventual salvation. I have a friend like that, who was wavering for a while until his kidneys failed. He has become as staunch a JW as there is, now that his life expectancy has shrunk and his general quality-of-life has decreased.
I don't know the right or wrong approach with your friend. I decided to leave my friend alone, because he is doing pretty well and is happy (he married a Philipino JW and moved to the Philipines, and is enjoying a laid-back existence with an ample pension to keep him comfortable). What good comes of trying to undermine his position? He would not be better off, is my view. I can't speak to your situation, though. It's not always an easy decision.