So Angry...

My 8yr old daughter is mixed half black and half white. Anyways she has a Musically account and she has her cousins on their and friends from school. Well today a girl from my daughters school commented on one if her videos saying "you're freakin ugly,you black ugly little girl" 😠😥😢 I asked my daughter who she is and she says, "I don't know her name but she goes too my school" I'm so upset and angry right now! How do I handle this? Do I drop it and obviously block her on my daughters account,do I find her at school and speak to her parents or do I go to.the front office and involve them??? Uhg,I'm so mad.

UPDATE : This morning I went to the office and the Principle was livid and he said they take cyber bullying very seriously. He asked if I wanted to make a report of the incident. I told him not until I speak with her parents first. He couldn't release the parents information too me but he said he can walk the campus with me until we find her and I can ask her myself and then go from their. We found her and when she saw me ,my daughter and the principle she tried to ignore us and run off. The Principle blew his whistle and made her come straight to us. I showed her her Musically account asked if that was her,she said yes. I said what it your Mom's name she gave it to me and I walked away. I found her Mom on Facebook and sent her the screen shot of what was said. She was absolutely appalled and very apologetic. She is deleting her daughter from all social media accounts and she is grounded for 2 weeks,she is also meeting us after school so her daughter can apologize to my daughter face to face.Im so happy that her Mom is being so proactive about this and hopefully this little girl learns a huge lesson!