She just needs to be educated about cannabis. She also needs to know why it helps you (besides the medical use, i.e. calms you down, makes you sleep better at night, social relaxation, focus...). If she is worried about the smoking part, get a vaporizer or ingest it. Make sure cannabis is not effecting your life negatively as well. If it is, then she is just worried about you. If she still cant look at it like a rational person, then I think its time for a change, if the drug means that much to you...