Should I report something I'm not sure is the entire truth to authorities?
What did you think was the truth?
I thought she was standing on my foot intentionally
I'm sorry that your foot is hurt, and you definitely need to tell on her. Honesty is the best medicine, and you don't have any regrets from keeping quiet. She needs to be punished for harming you.
Hey, who do you think you are? You don't know what's going on. You need to stay out of it.
I'm just here for you to vent to about your situation. If you feel like you can't be honest with others maybe talking to me and reflecting about the situation might make you come to terms if you want to tell or not. You should do whatever is best for you in cases where you are injured.