Your question raises several issues. The first is what you call harassment. There are two types, civil and criminal. As a criminal matter, the ex can be charged with a misdemeanor but whether the prosecutor will charge her is up to them. Your best and quickest way to get relief is probably under a civil action.
Under civil law, “Unlawful harassment” means a knowing and willful course of conduct directed at a specific person which seriously alarms, annoys, harasses, or is detrimental to such person, and which serves no legitimate or lawful purpose. The course of conduct shall be such as would cause a reasonable person to suffer substantial emotional distress, and shall actually cause substantial emotional distress to the petitioner, or, when the course of conduct would cause a reasonable parent to fear for the well-being of their child.
Note that it is a "course of conduct". That means that it is more than one time and by your facts, she has demonstrated a course of conduct with the numerous phone calls. Another thing to note is that "it would cause a reasonable person to suffer emotional distress. and shall ACTUALLY cause substantial emotional distress" to you. If you have not suffered substantial emotional distress, then the court will not find harassment. The third point is that the conduct must "serve no legitimate or lawful purpose." Thus, if the ex claims that you owe her money, or failed to pay bills you were required to pay, etc., then she may be able to convince the court that it is a legitimate purpose.
As to calling your employer, this may give rise to a separate lawsuit against her for slander and defamation. You would have to prove that you have been damaged. If she has no assets, then the lawsuit would only get you a piece of paper saying that she owes you money if you are successful. A defense to a claim of defamation and slander is truth. However, this conduct of calling your employer would also be part of your antiharassment petition. You can go to the Pierce County Superior Court and file a petition and ask the court that she be restricted from calling. Both you and your employer may be able to block her number.
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