Vaping, Electronic cigarettes

I didn't ask her if a boiling kettle affected her the same way

Probably not because kettle steam doesn't have PG (a known pulmonary irritant in itself), nicotine and whatever flavourings have been added to it :P

I've got asthma and it's surprising what can affect it, although I'd say vaping isn't surprising - pretty much any asthma/lung/general doctors will tell you that anything you put in your lungs that isn't really meant to be there can cause damage or irritation.