This isn't a case of your wife bringing, or dropping, charges. The DA's office will review the reports and decide if they think they can prove the charge, with or without your wife's cooperation. Your wife can have some effect by calling the DA's office, and asking to speak to the assigned Dep DA, or the victims assistance person (Though they don't really assist "victims" that want to drop charges).
As to the restraining order, that's part of your release agreement. It can only be dropped if the DA decides not to bring formal charges. If the DA does bring formal charges, then only the alleged victim can ask that it be dropped or modified, and courts seldom drop or modify it.
If you're charged, and if you have no prior's you will be offered the deferred sentencing program. That means you plead guilty, and go through classes, and if you complete the classes (18 months program) the case is dismissed. During that program, they generally have a 3 month period where you can't have any contact with your wife.
So, you're in for a long haul here. You need an attorney.