someone down below also said it might be Ur... I honestly don't know why shes so significant in this dragon fighting.
I know right, even Anna or Layla has a higher chance than being Ur. Hair wise, and dead/alive wise, since we never really know what happened to Anna (possibly not Layla as she's dead? or is she?), unless i missed something where she's DEAD DEAD.
Even Edolas Lucy has a more possible chance than being Ur, as they may have found a way to travel to Edolas and somehow magic has returned.
I GUESS, people said its Ur because the next chapter says "TEACHER". But people don't see how she doesn't relate to any dragon fighting, unless she has demonstrated ice dragon slaying magic.