I've been following this entire thread. Perhaps a compromise. I don't think that her smoking needs to be a "dealbreaker", but personally, I think it's very selfish on her part to smoke in your home and especially around your little son. If she's smoking in the house and car, you are both breathing in her 2nd hand smoke, and your little one smells like it, too. If she insists on smoking, make her do it outside.
My dad was a smoker, my mom was not, but after some tests, the doctor told her that her lungs condition was similar to his.
Hubby and I both smoked when we got married. Yes, we smoked in the house and in the car and around our children. We were young and selfish. After the children were grown, we continued to smoke in the house, but never when we had company or around the grandkids. Long before we started vaping, he quit cigs 3 years before I did. He used nic gum and had an occasional cigar on the golf course. At that point, I stopped smoking in our home and car. I will say it was NOT easy, especially in Maine winters, but I loved him enough to do it.
Be patient with your wife, but I'd insist she not smoke around you or your son. Settle yourself down before you talk to her. She should be the person you love most in this life, so show her by your words and thoughtfulness.
The Provari will give her variable volt vaping, not just 5V. A good choice is 3 ohm(standard) cartomizers. She'll be able to adjust the voltage up or down as she like. Voltage can make it cooler or warmer on the draw. I started with an ego, and when I went VV, I never looked back. Also, look into a cartotank like the Liquinator to make it easier for her because of less refilling. She also needs a flavor she likes, which is the hardest part for some of us. IMHO, there is a world of difference to higher voltage vaping. You can choose what you want your vape to be like.