You're friend can not take the fifth unless she somehow incriminates herself by testifying. For example, there are two  business CEO. CEO 1 is on trial. CEO 2 would take the fifth testifying in CEO 1's trial if he's testimony would incriminate himself.\n\nSince she is the victim of on assult I would say taking the fifth is not a logical choice.\n\nIt depends on the case as far as if she has to testify or not. The judge can make her come to court and testify by issuing a subpoena (which should be delivered by mail and/or a cop knocking on the door). If she chooses NOT to go to court even though a subpoena was issued she can be in BIG trouble and action can be taken against her. \n\nIf she doesn't want to testify she should go to the court house (as soon as possible) and get information from the District Attorney, Clerk of Court and/or the prosecuting attorney in determining whether she has to testify or not.