OP, I am deeply sorry for the loss of your child,i too have had a similar life changing event, my thoughts and prayers go out to you. Please take my advice as constructive not criticism...... I'm not going to dance around the issue as many here have in order not to offend , but the essence of your dilemma is not in giving your wife scientific evidence for the safety of vaping . You need To Man Up , yes Man Up and tell her politely but seriously that you are going to Vape,end of story........what she does is her choice after that . her attempt to control you is a plea from her for you to be the Man