The fear-mongering is ramping up right now, and trying to hit the mothers of America where they live. (Won't someone please think of the chiiildren?!) My friend who smokes actual cigarettes doesn't want her husband to vape around their kids, because she's afraid that they'll get nicotine poisoning from the vapor. I pointed out to her that he, and I, have been inhaling the vapor into our lungs for a while now and neither of us has keeled over from nicotine poisoning, but her fear is stronger than her logic. Which, I think, is what the antz are counting on. And I'm not talking blowing clouds in a toddler's face, either, I'm talking can't vape in the living room when the kids are in the kitchen, has to go outside.
Ultimately, you are an adult. It is all well and good for your wife to be concerned about you, and concerned about your kids, but she does not get to dictate to you what you can and can't do with your own body. She might tell you to go outside rather than vape around the kids, but she does not get to tell you you can't vape at all. My doctor vapes. She's ecstatic that I have quit smoking and started vaping. I pay her to help me manage my health, so I'm content with her endorsement. Yes, there are unknowns about vaping, and ten years from now we might find out that we've harmed ourselves by doing it…but we know for a fact that smoking will kill you, and most of us kept doing it for a long time anyway. People who have never tried to quit anything cold turkey are always willing to tell other people "why don't you just quit?" but you and I both know that doesn't work…otherwise we'd have done it years ago. There is an element of risk to everything we do, from drinking tap water to driving a car. Eventually, something will kill us all, and it will probably be unpleasant regardless of how clean we try to live.
I guess don't vape around the kids, if that's the major issue and will keep the peace in the home. I don't get the "don't talk to kids about your vaping" thing, because I don't believe that you should lie to children, nor do I think that they're dumb enough not to seek out information on their own if they really want to know about something. At least if they're getting the information from you you can be sure that it is the best, safest information you can give them. Maybe be sure to stress that vaping is for adults, that batteries/mods and e-juice can be potentially harmful if messed with, and don't make a point to make it seem fun to them. You're the one who has to live there, so you know best what you have to do to maintain good relationships with the people who love you. If it were me, I'd tell your wife and other family that you appreciate their concern, but that you are making the best, most informed decision you can about your health and that you feel like the possible future risks of vaping are far outweighed by the visible, concrete benefits of not smoking cigarettes.