The issue is not that works and faith are unrelated - they are. I think it is what most rational people would say is having integrity - practice what you preach, etc. We all know people who tout different values but who are inauthentic or even hippocritical because their actions do not match their words.
I think the issue is that JWs have a narrow definition of "works" and that they rank them on a completely made up and unofficial scale of spirituality. So while we have a wide variety of works demonstrated by Jesus - JWs only count a fraction of those as being worthy of replication. [i.e preaching and helping the poor in the congregation if they are "worthy"] If one chooses to express their spirituality by serving a larger population of poor or needy in some way (i.e Mother Theresa) it does not count because it is not "preaching" their current doctrine. Of course none of us are able to heal in the way Christ did - but there is healing that we can each contribute to others that demonstrates love on a much more fundamental level than even preaching - listening, encouraging, supporting, etc.
What I find interesting is that Jesus wove the meeting of the crowd's physical needs with their spiritual needs and he prioritized them: physical, then spiritual. In modern times, we may be familiar with Mazlow's heirarchy of needs. On the bottom are physical needs: sleep, food, safety, etc. Only when these fundamental needs are met are people able to think about the "higher" needs of spirituality.
As an organization, JWs biggest weakness is their black and white thinking and their limited acceptance of what "counts". Of course there is also all of the unwritten judgement that people do as they rate each other on how spiritual they are - and all of it - as far as i have experienced - is how well a person fits into the social hierarchy. And how well one fits into that social structure is based on what the congregation can observe - and it encourages a works for show type of atmosphere, a need to be visible.
I happen to be a successful single business woman who is open to marriage but not pining for a man. I am completely self supporting; live alone; have time and money to travel and am educated with a wide variety of interests. If I ever lost my mind and went back for some reason, there is no way I would pioneer. There isn't a slot for me in the congregation.
When I left, I was having panic attacks every time I walked into the building. Now that I only attend for weddings, funerals and the Memorial - I am MUCH happier, and able to be myself. I actually feel like a more spiritual person because I am able to express my reflection of love, acceptance, support, etc in ways that are appropriate to situations I find myself in. These for the most part are not observable to anyone else, and would not count in any way within the congregation.
ok, that was a long rant. I guess my short answer is to agree with your wife, and then ask what her definition of "works" is. And what types of things count. If she can broaden that definition, it will be helpful because it will open the way for her to be more open minded on other issues.