Can you and your wife offer to be a friend to the 19 yr old ? Reaching out not to be judgemental ,but just caring friends ? It could be beneficial for your wife if she sees how much better it feels to be just a normal kind person than one that must follow Watchtower policy .
I was raised as a Jehovah's Witness for 40 yrs . What helped open my eyes was seeing how the organization DID NOT reflect the message Jesus was promoting . Studying 'The Greatest Man " book at our book study started me thinking how much attention was drawn away from Jesus ,and to the GB.
About this same time a circumstance arose in our hall with an 18 yr old girl that needed some help . I found out then that the 'brothers' had no idea how to apply the 'good samaritian ' lesson from the Bible ,all they could do was parrot 'Society' guidelines that we should be more involved in the preaching work than 'social' work . This was the beginning of the end for me . When you personally witness how cold ,and unloving the organization truly can be it is a slap to the face . It happens all the time ,but goes unnoticed until it personally affects someone close to you . The Elder body is more about finding fault than helping out ....this happens every where not just your hall !
Keep focusing your wife on how this situation could be handled better by just showing love .
When I quit attending I read Romans ,and Acts without the Watchtower influence . I also listened to a Minister give a discourse on those books of the Bible ,and I was touched . Love ,and Grace were explained in a way I had never been taught all those years as a Witness .
Over time I have come to my own conclusions about God,religion,and the Bible . Which are far removed from where I began .
Best wishes to you and your situation .