ДНК S07E150 - Выпуск 1023. Производительница детей

After school, Ekaterina went to her aunt's for lunch, and she informed her that she was not her own, but an adopted daughter, and that she had six or even seven brothers and sisters named Medina. That's just that in a large family of Media there was never a younger sister Katya, but there was a younger sister Natasha. Ekaterina also assures that her adoptive parents did not change her name. So is she an unknown sister or a namesake?