TV Legend Betty Buckley Joins ‘Supergirl’ @tvinsider https://t.co/zAxzuJPJtL
— Betty Buckley (@BettyBuckley) September 29, 2017
According to The CW, the Arias women have been estranged since Sam became a teen mom and "their relationship is made all the more complex by the secrets Patricia holds." Given that Sam is actually Reign, the genetically designed, world-killing weapon we first peeped in May's season finale being sent to Earth from a cabal of hooded Kryptonians before the planet exploded, it's highly possible that one of those secrets the "honest, but stubborn" Patricia is sitting on includes the still-unaware Sam's otherworldly and lethal origins.
Buckley is set to make her first appearance in "Wake Up,' the third season's seventh episode.