armed robbery involving juvenile

What is the name of your state? North Carolina
17 yr old dtr could possibly be involved in a robbery with a gun,and might possibly have set it up for the boy she was with to be robbed. she has not been charged (yet) but I told her to turn herself in if she is guilty. should we obtain a lawyer first before she ever goes to the police and admits her guilt? Also, would she be dealt with as an adult or a juvenile? Could she possibly be a state's witness if she supplied info on who actually did the crime? she didn't do it but was there and apparently aided in it happening.pls help

get an attorney first. let the attorney try and deal with the prosecutor. the police cant make deals on charges against her.