Should i confront her at her school?

there is this girl that made up a rumor about how i supposedly went around asking people that if the guy i was talking to had STDs. she told him and his sister and got him and i to stop talking do to her lies. It makes me so mad tha tshe would lie about this and especially since he went off on me called me a slut and a *****. I want for everything to be cleared up and for him to know that she lied. i dont want anything with him like that i dont even want to have any ties with him, i just dont want her to think she got away with what she wanted and tought it would be okay to do and have no consequeneces. im not gonna be violent i just wanna talk to her and get her to tell him the truth or atleast confront her with him and me to see if she has the to lie to my face. there is no other way for me to talk to her face to face besides my job but i dont want to bring drama into my job...is it stupid of me to wait for her after school to try and clear things up?