"should I be filing a complaint with Child Protective Services because they don't tell you who files the complaints that lead people to point fingers at other innocent families ?"
You can file a complaint. However, you should not expect the complaint to go very far. The government encourages people to report suspected child abuse. If the reporter does not want his/her identity known, the government is not going to release the identity. There is in fact no requirement that the reporter identifies himself/herself when contacting CPS. As long as the reporter provides details that suggests to CPS that an investigation is needed, CPS will investigate.
I agree with the previous responses. In addition, you may seek an anti-harassment order against an out of state resident. There will be some issues of jurisdiction; however, the contact with you in the State of Washington should satisfy the court. Your obstacle will be proving the contacts via text messages came from your step-mother.
Peter J. Abbarno practices in the State of Washington; primarily in Thurston, Lewis, and Cowlitz counties. The response is limited to his understanding of law in the jurisdiction in which he practices and not to any other jurisdiction. No response to any posted inquiry shall constitute legal advice, nor the existence of an attorney/client relationship. www.centralialaw.com