Your granddaughter would have to go into a local district court and request an anti-harassment order petition. She would need to fill out the petition and allege truthful facts that set out how she was being unlawfully harassed.
RCW 10.14.020 defines unlawful harassment as:
“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.”
Furthermore, “course of conduct” means “a series of acts over a period of time, however short, evidencing a continuity of purpose.” RCW 10.14.020(2). Constitutionally protected activity is not included within the meaning of course of conduct. Finally in determining whether a course of conduct serves any legitimate or lawful purpose a court should consider whether:
(1) Any current contact between the parties was initiated by the respondent only or was initiated by both parties; (2) The respondent has been given clear notice that all further contact with the petitioner is unwanted; (3) The respondent’s course of conduct appears designed to alarm, annoy, or harass the petitioner; (4) The respondent is acting pursuant to any statutory authority, including but not limited to acts which are reasonable necessary to: (a) Protect the property or liberty interests; (b) Enforce the law; or (c) Meet specific statutory duties or requirements; (5) The respondent’s course of conduct has the purpose or effect of unreasonable interfering with the petitioner’s privacy or the purpose or effect of creating an intimidating, hostile, or offensive living environment for the petitioner; (6) Contact by the respondent with the petitioner or the petitioner’s family has been limited in any manner by any previous court order. RCW 10.14.030
After filing the petition, the court would set an ex-parte (one sided) hearing to determine whether a temporary (2-week) order should issue. If the Court grants the temporary order, it would set a hearing for a permanent order. The temporary order and the notice of the permanent order hearing would have to be served on the opposing party. This is usually done by law-enforcement, but can also be done by any adult who is not a party to the case. The opposing party would then have a chance to argue that the facts in the petition are not true. After hearing from both sides, the Court would either grant or deny the permanent order. Hope this helps.