Look, up in the sky! It’s … Claire Holt? according to Thewrap.com Holt, who plays Rebekah on the CW’s The Vampire Diaries and its offshoot The Originals, is among those testing for the lead role in CBS’s upcoming comic-book adaptation Supergirl. On 13 January 2013, The CW announced that Holt had joined the cast for the backdoor pilot of The Vampire Diaries spin-off The Originals, where she reprized her role as Rebekah Mikaelson. She exited the show as a series regular in the sixteenth episode of the first season, which aired in the U.S. on 11 March 2014. Holt returned as Rebekah Mikaelson in the season one finale on 13 May 2014.
Her absence from CW's vampire shows, makes her a good candidate for the role.