Honestly, IMO, vaping is a safer alternative for those of us looking to stop smoking and regain some of what we've lost over the years. Whether it's health, taste, smell, etc - if she's never smoked a day in her life, there's really no reason for her to pick up vaping. There's no 100% guarantee that vaping, in and of itself, is 100% safe - it's an alternative to smoking and should be treated as such.
My wife doesn't smoke, and never has and if she expressed interest, I'd ask why given that fact. I don't see any logical reason a non-smoker would be interested or have a desire to vape if they never smoked, dipped, etc - i.e. if they aren't looking to get away from something more hazardous.