The Coregency Stela (UC 410), mentioned earlier, might resolve the question if it were not so badly damaged. The name Neferneferuaten replaced Nefertiti's name on it. How the image of Nefertiti was changed to match the new inscription could settle matters if her image was not missing. If her entire image was replaced it would mean Nefertiti was replaced by someone else called King Neferneferuaten and perhaps that she died. If just a new crown was added to her image, it would argue quite strongly that Nefertiti adopted a new name and title. As it is, the scene seems to be another of the royal family including at least Meritaten. Replacing the name Nefertiti with the name King Neferneferuaten in a depiction of the royal family, still seems to favor Nefertiti as the new king.