Why bother?
If you are doing e-cigs to off yourself of the real thing, you don't need anyones approval or blessing...simple straight...and period.
You already know her attitude and I see little advantage in trying to please or appease her.
I don't know your past addictions and it is none of my (our) business. I do know that these are a great alternative to tobacco.
If you do your research, I think you will find e-cigs attributes are positive over real cigs by a large degree. My doctors (both) are intrigued and glad I am using them and the Holistic doc was thrilled with the ingredients, and talked to me about how well they are metabolized in the system and are basically ...... out as lactic acid.
But do your own studying on the subject, and don't cow tow to the fools.
...... Pig