A post on PSNI City Centre says the youngster is 5ft 7ins tall and slim with dark hair.
The post adds that she is missing from the Bangor area.
It adds: “Last seen wearing a pink headband, black track suit with white stripes, black leggings and carrying a backpack.”
The post asks anyone with information about Rihanna to call Police on 101 quoting reference 1619 of the 27/02/22.