Shinaiah was last seen at her Joefield Trace, Lambeau home in Tobago at around 7:15pm on June 19th.
She was reported missing to the Scarborough Police Station on Wednesday by her mother, Kelleisha Marcelle.
Shinaiah is of African descent, 5 feet 10 inches tall, stockily built, with a dark complexion and a relaxed hairstyle.
The teenager was last seen wearing a red t-shirt, a pair of black jeans and a pair of black sneakers.
Anyone with information on the whereabouts of Shinaiah Marcelle is asked to contact the police at 999, any police station, or call 800-TIPS.