Wondering what to do to this?

Okay so today I am friends with this girl. Shes one of the most popular girls in my grade. In one of my cles i sit next to her. I am a boy. Today in the cl i have with her, i was packing up. One of her friends came up to her and accidentally pushed her water bottle with her bag. Meaning the friend carelessly went up to her, didn't care what her bag was doing, and her bag accidentally pushed the water bottle, spilling some of it. The pretty girl started to accuse me of pushing it and I kept on saying I didn't. She kept on going and I said 'shut up' to her. She's kinda angry at me and I apologized to her and I have no idea what else should I do?