Generally, communications like you describe such as filing a complaint would not rise to the level of a violations. A letter demanding payment, however, could be. I would talk to a lawyer about what you plan to do first, this way you would know if you are on firm legal ground or not.
Whether or not this breaks the PPO . . . check with a local attorney
OR see the judge that issued the PPO (or his clerk).
If you DO file this lawsuit (pro se) then you HAVE to have a process
server serve her as the proper service. Don't send her any letters.
Once the lawsuit is filed petition the PPO court to explain (or ask
for permission) to mail her the discovery, etc.
THIS ANSWER IS PURELY FOR ACADEMIC DISCUSSION ONLY AND DOES NOT CONSTITUTE ANY TYPE OF LEGAL ADVICE OR LEGAL REPRESENTATION.