Alura Zor - El (portrayed by Laura Benanti in season one and two, Erica Durance in season three) -- Kara 's biological mother who is the twin sister of Astra In - Ze. Alura 's guidance (both in flashbacks, and as a Kryptonian Artificial Intelligence which acts as Kara 's holographic virtual "mother '', whose advice Kara can access in the present day) proves invaluable in Kara 's journey. Due to a fail - safe that Zor - El built around Argo City to protect it from Krypton 's explosion, Alura is still alive and is part of Argo City 's High Council.
who plays supergirl's mom on the tv series
Laura Benanti