What happens when you get charged for battery or assualt?

Hello,
My ex-girlfriend slapped me and I want to press charges, we have a son together so thats a bit of a concern in this. I am 18 and she is also 18. We have court this coming Monday. So I want to know first what would she get charged with(battery or assault) and what is the punishment for that. For example, staying on your record for how long? I know this will result in child support and custody battle, which is going to be a tremendous battle and is going to be rough because I want to know if any pro bono lawyers handle this or if public defenders would do a good job. I am really lost, so any help is greatly appreciated. Thanks.