I'm guessing that the 0 nic might be the one that gets added. I'm at 6 mg now, but I wanted a higher nic ejuice for those times when I wanted a little oomph so I recently bought a bottle of 12 mg. Put some in an an Ego Mega styled tank (TW CLL) with a .8-.9 ohm SS316L coil and the throat hit was too much for me. I have to run it in a resurrected Mini Pro Tank II to use it. Heh.Thank you so much for sharing your experience! The tank and coils do make a huge difference. When I quit I was using a Joyetech AIO with the 0.6ohm MTL coils and 12 mg was too much for me (I smoked 15 to 20 light cigs a day). I think the 12 - 18mg range should cover her and I'll take an extra 2 bottles of unflavored (one at 18mg and one at zero mg) so she has options.
Hard to tell what a neophyte will like tho - we've probably all forgotten to some extent what a real cigarette throat hit feels like. I have anyway.
Also, some people have a real problem at first with inhaling vapor; something about the hot vapor makes them cough a lot.