This Is Us actor Krys Marshall has joined the cast of CW's Supergirl, according to TVLine. Marshall will play Julia Freeman, a musician with mysterious ties to the villainous Reign.
There is no Julia Freeman in DC Comics lore, however there is a Freddie Freeman - a.k.a. Captain Marvel Jr. Additionally, Marshall bears some resemblance to the New 52's Power Girl, Tanya Spears, who, like Supergirl's Reign, had a mysterious past and secret superpowers.
The original comic book Power Girl, from whom Spears inherited the mantle, was actually the Supergirl of Earth-2. Given that connection - and Reign's New 52 origins - it's possible that we could see a version of this character appear on the show.
No further details about Marshall's Supergirl role, or in which episode she will debut, were given.