Welcome to the forum! I'm glad you are reaching out.
It gets kind of tricky to go and ask someone to take a psych test. Someone with BPD has to want to seek help for themselves... .in all honesty that goes for anyone. As difficult as it is rescuing or trying to help fix someone without them asking or reaching out first usually doesnt have the best results.
So what do you do?
Well what I think you should do first is focus on your own well being. Alot of the skills you will need to learn if she has BPD or not are great and will improve any relationship. Taking care of your own physical emotional and mental health will be the most beneficial.
My partner and I had some rough crazy times so I know all about dysfunction. But I knew that the only thing I could change about us was changing and taking care of myself first. I was struggling with so much anxiety and depression and anger from our relationship I had to get that together first!
I did that through my Faith in God, getting my health together, and learning skills to improve my emotional and mental health. Getting counseling as well. These things really gave me my life back. And better equipped me to handle the challenges that will undoubtedly arise when you are in a relationship with someone with BPD.
I really like this book "loving someone with Borderline Personality Disorder" by Shari Manning
It will give you a crash course about the illness and has a ton of practical tools on improving your relationship. And in all honesty the tools are helpful to know even if you discover that she might not have BPD.
www.amazon.com/Someone-Borderline-Personality-Disorder-Control/dp/1593856075Good luck and peace to you... .the fact that your here shows you love your wife very much and really want to have a better marriage. You are already on the right road to improving your relationship!