Communicate with the teacher directly

tell her what your daughter told you and ask whether the teacher had seen the whole process, whether there is a chance that the teacher only punished one side. Tell her that you don't mind kids being educated on not to hit others, but it is also important to do it fairly so that kids who are not able to fully communicate their ideas do not get punished unfairly.

communication is always the key. As long as you communicate your ideas to them, they will be careful next time. Also encourage your D to explain her situation loudly. Start from home with Chinese. Don't always ask her to be obedient, but allow her to talk back to the parents all the time.