In 1991 at 14 years old and "dating older men" this was not a willing drug user. Someone got her addicted to control and abuse her. It makes me wonder how young she was when the abuse started, and as she grew/matured and attempted to assert herself, they simply drugged her.
This poor child is not a runaway, she's likely a homicide victim. We all want her to have run off and start a new life, but lets be real. How is a 14 year old child back in 1991 going to do that? Look at her photo, she's dead inside, someone killed her spirit. Bless her soul, I hope she's found and laid to rest or found and is happy!