Yeah, and those people were controlling her son's mind, to the point that he betrayed Cersei. Arya just killed, what, +50 people in the last episode? Is she evil, too? Killing people in Game of Thrones doesn't make someone evil, because if it did, everyone would be evil.
Arya is definitely evil. On a scale of 1-10 with 10 being Ramsay, Arya would be a 8 right now. She killed innocent people before. She butchered someone, made a pie out of it and fed it to an old feeble man.