If she and her guardians want to press charges on you, they can and will. And since I see you are filing a police report they will assess to see if you are a flight risk, whether you will run or not. If you are considered a flight risk, you will be detained until they figure out what will happen. If not, you just go home.
If the girl decides to press charges you are looking at assualt and battery charges. You can be charged as an adult. If you are tried as a juvenile, you will see about one month of Juvenile Hall time and a lengthy probation time, which will consist of an ankle bracelet.
If they decide not to press charges, nothing happens.
Seeing that you were the aggressor, nothing will happen to her, perphaps terrorist threats, but other than that, nothing.
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God Bless