She ran after her because she was literally headed into a restricted zone, plus it wasn’t even intentional to find her, she randomly saw the supposedly nice heroine who she didn’t really have interest in/viewed as a non-threat heading into a dangerous area where she wasn’t supposed to be, literally it’s the same as yelling at someone cause their trying to go backstage or in the teachers or workers area, you see someone heading into an area their not supposed to and you warn them, plus she didn’t try to interact with her much beyond worrying about her basic safety, which is a pretty common reaction when she knows the person heading into said area, and even then she disengaged and starting taking into account her behavior that definitely was deviating from the actual plot/heroine she knew
If the mc was going to leave the heroine and write her off as being fine anyway why tf did she run after her in the first place (￣∇￣") what a waste of panels(╯°Д °)╯╧╧