Injustice 2 #6
Get ready for the Origin of Supergirl! Jump back in time to see the early life of Kara Zor-el and the destruction of Krypton. Sent to Earth to be her infant cousin Kal-el's protector, an accident delays her by decades. She's met upon her eventual arrival by a most unexpected benefactor and learns a very different version of the story of Superman's regime.