User blog comment:San&Ashitaka/Chapter 51/@comment-17563801-20131108224056/@comment-162.206.106.194-20131202212627

Or how about she was an ordinary Titan until she ate Reiner & Berthold's friend, thus aquired his Titan shifting ability?(I think we can safely assumed everyone that came from Reiner's village possess the Titan shifting ability) Then she was be able to turn back to her human body with her newly aquired ability? This just popped to my head but I think it made a lot of sense.