It is thought that Vandi swallowed "Otapiyapiya," a deadly chemical found in the area.
The development was verified by Adamawa police spokesman SP Suleiman Nguroje in a statement made on Wednesday in Yola.
The deceased, a native of the state's Michika LGA, took her own life by abusing a local drug in protest at her boyfriend's passing.
"She made the terrible choice shortly after her boyfriend, Nuhu Boniface, passed away in the hospital while undergoing treatment," the statement reads.
According to Nguroje, the girl was employed by Girei Primary Health Center as a health worker.
"Police Commissioner Afolabi Babalola has conveyed condolences for the incident and advised the public to report any suspicious activity in their neighborhood and refrain from enforcing law enforcement action."