Me and my sister and mom were caught shoplifting, I took over $300 worth of stuff and my sister over $200 and mom over $100 what is going to happen to us?

Where?

Depending on your age and that of your sister I see Family Court stepping in - perhaps your Mom will lose custody, perhaps not, but she faces a very stiff charge of contributing to the delinquency of a minor (if you are a minor).