Hi, and welcome to ECF. Glad your GF is switching to
vaping and certainly learning about it (and vaping 0 nic yourself) could be a great help to her as she transitions from cigarettes. This is one of the few times where I actually could see a non-smoker taking up vaping and it being a net positive.
I will merely note that many recent scientific studies coming out are finding vaping very much safer than cigarettes, but that at this time we don't have a ton of longitudinal data concerning overall safety with ecigs, simply because they haven't been used enough by many for enough time to capture that kind of data, although early indications are promising.
Best of luck to you and your GF, and I hope the transition goes well.
Anna