The killer was abused, yes. She believes that she's the original one.
But she also believes that there is a connection between her and Sarah. She believes, she somehow SEES that Sarah is different from the others that she's killed. Why? Why is that?
Kira saw right through her aunt Allison's disguise. I don't get how. Children really do have a connection with their parents, huh? Would we all be able to see through our parents if they weren't our real parents but clones?
For another matter completely, how did Katja find about Beth, Allison and Cosima but not about Sarah? How in the world could Sarah have just dropped out of the blue like that? Who's Danielle and do the other clones know?
I saw the preview for the next episode. I knew that things were going to become like that... AH! I need to watch more! So many questions, they better get perfectly matched with good answers!