Mostly her own words. When she was questioned during her trial, she claimed that she never took another life directly. She also said she much preferred to have her flag with her than her sword.
It's a minor thing, but I find it amusing that a young girl was so fond of being extremely aggressive. IIRC, there was this one instant where she told her generals that they would need to get their horses ready just in case. When asked if it was in case they needed to retreat, she berated them and said it was to chase down any stragglers. That said, she was a very kind and gentle girl outside of battle.