Hi Kent. Could you extrapolate a tad as to how she "got the routine down"? My wife coughs as well. I even tried changing from a PG based liquid to a VG based one. No dice. Miss cough-a-lot lives, unfortunately. Thanks...
I find, as did the wife, that a few short cigar or pipe type drags helps, couple drags, open the mouth a bit, take in some air and then a staight drag/inhale (not a lung inhale - that _will_ make you cough at first lol. But, you might want to try that too ;-) And that is more in common for the auto but I still do it on the 510, but also hitting the button a second or so right before a drag and you can drag just like a cigarette.
All VG is not created equal - the stuff I got from Nuvape while creating good vapor had an off taste for me - not terrible though and it mixes well

with other stuff, but ECOpure from Innovapor is really nice, imo. 'Fresh' is really good and then Rich, Regular and Mild in that order but all pretty good. I sometimes use Fresh to pump up the volume on RY4 - I think it tastes a bit like RY4 anyway but the vapor is huge with ECOpure.