The girl and the ghost

Today, breaking with tradition, I noticed her.    
She offered me an anemic closed-lip smile.    
Her eyes flickered, but beheld nothing.    
Some sad song sang through her bones.    
   
At age 11, she was an irenic soul.  
Chamber rooms brimmed  with her laughter.  
She often rode her horse at breakneck speed.  
At age 18, her suitors were many.    
   
I found nothing of that once charismatic colleen.  
Conversation only pained us both.  
She strived to be a ghost.    
I could guess at the source of her pain.  
   
By 20, one young man had captured her heart.  
She implored her father to give the man a horse.  
She invited her suitor and her guests to see.    
Stable opened, they beheld the pale horse.