Do walmart prosecute 15 year olds for shoplifting?

My niece just got in trouble with stealing $43 worth of make up. She is 15 and they had called her parents to come pick her up. However, the cop was there and he just took down her name, phone number and her address. Walmart said they were going to send us a letter in the mail for the fine, but the cop said we will receive the court date in the mail in about 2 weeks. Does walmart prosecute 15 year olds? iS it possible that the cop said that to scare her? and should we get a lawyer?