I'm going to confront my friends new friend who is trying to give him adderall
Why do you want to confront her?
I just don't like her and what she is doing. I think she is the kind of person who influences my friends in a bad way with their drug habit
It is hard to confront another person but if you think that they are going to harm your friend it is understandable to want to interfere. Your friendship could get stronger.
How is confronting her going to make our friendship stronger? And is she going to get arrested? That's what I'm aiming for.
What I meant to say is that your relationship with your first friend will be strengthened if you can keep this potential drug-pusher away.  I don't think that you can get this other person arrested unless you can actually catch them in the act, and that is just too risky for you to get involved in.  It's best to just keep looking out for your true friends, as you have been doing.