Alexa The Dark Witch

Alexa Jocelyn Heart is an orphan because her parents abandoned her in an orphanage. She grew up with unusual physical characteristics, compared to other children her age at the orphanage, which made it difficult for the girl to make friends. 
Things got worse when Alexa was a teenager. She cursed a girl who was a rival there for wanting to burn her room so that the enemy's body turned to ashes. 
What is the fate of Alexa next? Who is she and what power does she have?