she might revive, but the cost would be huge. On top of the potential cost of this 'miracle'(some sort of sacrifice wpuld make sense), being a mortal prevents her to be with yato much more time anyway. It's better for her to remain a shiki...
the worst conclusion would be to pull a Dbz wish and...
waait aren't the bad guys planning a huge mobe on that deviculum? maybe they will reveal that Iruma is human. Fortunately Ameri does know so she can defend him if they go together.
I just remembered.. she is aware that iruma is in fact human, right? I got lost in that topic because she kind of forgot it after the first reading sesion