How much jail time for child abuse with serious injury?

My ex girlfriend was finally convicted of child abuse with serious injury. She was tried by jury. I don't know if cirstances affect the sentence but the abuse was on her 6 month old child. She is also the mother of my 2 year old son who was also abused but not enough evidence to charge her. The whole case took like 8 months because she kept trying to get off on some mental instability plea. ( she is crazy but she knew what she was doing) also i share share custody with her mom since i was a suspect when my son was abused. I have been cleared since that case. Am i legally able to file a restraining order on behalf of my son even though her mom will of course try to stop me? I have joint legal and joint physical until Jan. Then i will get full custody. But my fear is that my ex will get out when she get's sentenced in Dec. This is in the commonwealth Virginia by the way.