She is voiced by Alyson Stoner, who also voiced Isabella Garcia-Sharpiro.
She's also a love interest of Bolin.
Order of the Just and Blue Team
Along with Davis, Matt, Dan, Mustang, Shadow, Mitchell, Elsa, Heavy, T.K, and Yolei, Opal is in line to become a member of the Order of the Just.
For right now, she's a member of the rebuilt Air Nation and is also a member of the Blue Team along with Bolin.