I can hardly see her turning in going well. "Invisibility Borealis? At this part of the year, at this part of the day, at this part of the country, localized entirely withing you body?" It was a street at the time, when people go to/return from work, and no witness saw her. If she insist, she can be directed to the mental ward, if we speak realistically. Of cource, she can stab somebody else, but I doubt the possibility of this. She still didn't told her mother, so there's some potential for drama. But her friend looks like she understands, how ridiculous this plan sounds, but she doesn't want to upset her.