Answer:
It is considered to be a bit disrespectful to write to a teacher in an unprofessional, casual manner, the way you would a friend because you aren't close on a personal level. Of course it depends on the teacher and subject of the letter/email/etc. as well. 
 
        
                    
             
        
        
        
This is more of a personal opinion as it is not directly indicate what she was,. she was most likely a ghost as she was already dead and it would have been very unlikely for her to come out from being buried alive. She is also a metaphor showing how the house would die along with the family.
        
             
        
        
        
Find ways to understand something better
        
                    
             
        
        
        
"<span>There was no deceiving himself: something terrible, new, and more important than anything before in his life, was taking place within him of which he alone was aware. Those about him did not understand or would not understand it, but thought everything in the world was going on as usual."
-This excerpt shows that only he alone knew that there was change going on in the place, one that is not good, & no one else seems to notice.
hope this helps</span>