Yeah, with her running .5 ohm coil, I would not recommend any higher than 6mg IMO. I run 24 mg all the time but that is with my MVP and Emow tank with 1.5 ohm coil @7 watts.If you don't have much of a desire to smoke.
I'm with some of the other folks here, 3mg sounds very low. That would not have been effective for me. There were times I needed 24. Ok, that was on the relatively lame gear of 2+ years ago, but still...