I was stalked by a gay male for three years, who i had befriended in highschool and later cut off because of threatening remarks he made about hurting his own family members. I didn't know he was gay at the time, but he kept sending me long letters and following me around places. He followed me into the bank one time and made threatening comments; every time i went to the police they did nothing for me, even with the letters as evidence. It eventually culminated in him following me home one day, where i barricaded myself inside with a firearm; he fled before police arrived. They took the report but did nothing further.
No law enforcement took my complaints seriously because I was an adult male, and they pretty much told me to "take care of it myself". Keep detailed records of the encounters with her, and ccw in case you need to defend yourself against the mentally unhinged.