my wife was in a car wreck and says that the car hit her but the police said that it was her falt what can i do to reverse the the charge

Contest the ticket in Court. If it is clear they are intent on getting a guilty verdict, a nolo plea should not be admissible at a subsequent trial.  Parts of the Officer's report MAY be admissible, depending on the officers experience and training (i.e. in accident reconstruction).  Most DPS officers are, and local /county less so.