Could we be seeing a dynamic duo come to life after this crossover between Sara and Alex? Probably not at least regularly since they live on two separate Earths.
Too late for Spoiler Alert...Eobard Thawne (for some reason looking like Harrison Wells) is the Dark Flash on Earth-X. You read that right, not Reverse-Flash, but the Dark Flash.
She was my sister. I couldn't be angry because she was dead. I couldn't grieve because I was so angry, that's what happens when your sister dies while screwing your boyfriend.