It's good that you are gathering knowledge of what BPD/NPD is, and that you support your wife seeking professional help. Has she mentioned that she wants to go to counseling, or has she been before and had a diagnosis?
It is said often on this board that telling their partner what they are (BPD/NPD) and forcing them to do therapy can have all sorts of negative outcomes. I'm sure that the members on this board can share their experiences and advice with you about that.
If you take a look at the Lessons (see quick links to the right of the screen), you will see there are many aspects of working on maintaining a relationship such as yours. Such as, finding inner strength and hope. There is a great workshop on taking care of yourself through all of this... . what some ways that you are doing this?
You can check out the workshop here:
https://bpdfamily.com/message_board/index.php?topic=112473.0