Little to none is known about Demetria since she hasn't made an appearance in the series yet, but here are informations gathered:
According to Imaw (when he was narrating to Amihan the past of Sang'gre Adhara), Demetria was the queen of Lireo before Mine-a, she had a daughter named Esmeralda but she died before Demetria. When Demetria died, she was alone with no one to take her place at the throne (as what everyone thought). So her niece, Adhara, thought that she would be the next queen of Lireo since she is the closest relative to replace her, until Cassiopea took away the crown and told her that she will never be queen, because Demetria already has a successor, which is Mine-a, one of the daughters that Esmeralda left.
- Unlike her counterpart character in the 2005 series, Demetria is of royal blood, her counterpart however is not.