While it's generally good to avoid confrontations and walk away, it's a good idea to know atleast basic self-defense. School was a terrible experience for me as people with low self-confidence tend to make easy targets for bullies. I hope your daughter gets through school without much trouble. Please do support her. Sometimes it's not easy for kids to tell people cuz of ego or just the general distrust for adults. Also whoever thought putting a bunch of puberty riddled kids into one room was an idiot.