Two more supporting roles for the upcoming Supergirl TV series have been filled, DC has announced.  Chyler Leigh (Grey’s Anatomy) has been cast as Alex Danvers, Kara’s foster sister who, true to type, becomes a doctor.

David Harewood (Homeland) has been cast as Hank Henshaw, who runs the department of Extra-Normal Operations.

Calista Flockhart was announced as a regular as Cat Grant earlier this week (see "Calista Flockhart in 'Supergirl'").  Melissa Benoist (Whiplash) is playing Supergirl, and Mehcad Brooks is playing love interest Jimmy Olsen.