sanjay gupta gave a really well done and nicely detailed description of what goes on with this type of injury.
he mentioned the following things:
the shot went from the back of her head and out the front left temple/forehead.
the bullet going “through and through” meant that most of the bullets energy was expelled outside of her head.
that bone fragments from where the bullet entered would have been removed from the brain and any brain tissue that was damaged would be removed.
the left side of her skull would be removed and placed aside on hold until they are sure that brain swelling is over (about 4 months).
he seems to think that things look good with her responding when they lower the sedation.