Ever since her debut in the pages of "Brightest Day", Siren, Mera's sister has also been referred to as Hila; so just to set the record straight, know this: Siren and Hila are not the same character. Geoff Johns has stated (NYCC 2010) that he was being very careful in ensuring that the distinction was made. Hila was Mera's twin (identical) sister, while Siren is her younger (non-identical) sister. Whether this is a moot point with the new continuity or not, that remains to be seen. Thing is that if the new Aqualad, Jackson Hyde still exists in the DCnU, we still don't know who his birth mother is. See where I'm going?
Siren leads Xebel's attack of the surface world