Do I have a case for Slander in this situation?

I am a mom...the mom who did this should have addressed her concerns through the school instead of confronting you on school property. For this, the principal should have a talk with her. Unfortunately you do not have a case from what my cousin the attorney stated to me. If someone rides on your lawn with a bike and leaves tracks on your lawn, you have a case but if someone simply rides on your lawn without causing damage, you have a difficult case. First of all the mom has free speech. She used a very immature way to express it. Secondly, you were not damaged financially. What you could do is place a police report stating that you were yelled at by an adult on the school grounds and it was very upsetting to you. There may be some criminal fall out to it for her. I remember years ago a neighbor was screaming at me and I called the police. when they pulled up she was still screaming, so they arrested her for disturbing the peace. Your principal has some responsibilities. You need to feel safe on school grounds. I would talk to your parents and file a formal complaint with the school. Maybe they can tell this mom that she can't ever do anything like this again and that it was very inappropriate!