A favorite JW scripture; Faith without works is dead. In the book of James somewhere. If you quote that scripture to any JW and ask what it means, they will describe the works that faith produce; preaching, meeting attendance and the general JW lifestyle. JWs feel that these works are evidence to identify their faith as the 'true faith'.
In context the scripture in James has nothing to do with preaching or typical JW works. It is about being hospitable and charitable towards others. JWs are not exactly focusing their ministry on looking after orphans, widows and giving food and shelter to the needy, but many people, Christian and non Christian, do these things. Maybe showing your wife scriptures like this, and seeing how JWs cherry pick scriptures and take them out of context to support their theology might help her wake up. You have to be subtle obviously. You could talk about the scripture in Corithians I think, that says salvation is not earned by works, but through faith. This one does not get a lot attention from the JWs, because they are a works based religion.
2 Peter 3:9 Is basically saying that Jehovah is delaying Armageddon because he does not want to destroy people but wants all to be saved. This scripture is in clear contradiction to WT theology, because the worlds population is increasing at a far greater rate than those that are coming into Jehovahs organization. It means that every year that Amargeddon is delayed, an extra 70 million+ people that will have to be destroyed.... if JWs are the only ones that will survive, which is what we are taught. This does not make sense, something to talk about maybe. All the best.