Supergirl Cameos In The Flash Tonight, And What That Means For Their Crossover Story

By Russ Burlingame Warning: Spoilers ahead for tonight's episode of The Flash, titled "Welcome to Earth-2."Yes, folks, that was Melissa Benoist as Supergirl that you just saw on The Flash.And, since Barry Allen was moving through a breach in the multiverse, it's likely safe to assume that she comes from a different Earth.While more