just be up front with her bro. if you hide it right from the start, then it is already dishonest at the start. if you like her and want to advance it at all, i would just be like, "there is something you need to know, and i dont want ot hide it from you, but i do use steroids to a degree." reassure her you know what you doing and be ready for questions. respect her response which ever way it goes