Just tell her the truth, Its better than, and less dangerous than alchohol+cigarettes.

That knowone has ever died from marijuana and that alchohol and cigarettes are the biggest killers in terms of drugs.

Not that I'd really consider weed in the same league as what I'd call REAL drugs.

If she isnt comfortable about it, don't force her/pressure her, even If it all turns out well and she loves it, still aint right to impose something on someone.

Jonny