I have seen the word 'chimera' used by various writers. Usually they use it along with 'dreamy / dreamlike' or whispy' and so forth....all having positive connotations. Yet, it is the opposite and it would be more correct to think of monsters and the macabre (A grotesque product of the imagination) when using this word.

Somehow I cannot tie that in to the image of the ghostly girl....she speaks, to me, more of dreams unfulfilled, of sadness and opportunities lost.