There is a human version of twilight already in the equestria girls universe but she is going to a different school, imagine it like this: Canterlot high is ponyville before Twilight sparkle is sent there to learn about the magic of friendship and the actual human twilight is still in ''Canterlot'' doing her advanced studies, I know it doesnt make alot of sence but thats the way i see it. Pinkie pie does mention that there already is a twilight sparkle in the human universe with a pet dog named spike
