Are you still around, and interested in someone commenting on this?
I have to comment on your premise.
"Mary-Anne Collins spent years living under the oppressive reign of her abusive husband. After his passing in a car accident, Mary-Anne felt she had a new life ahead of her. However, something sinister has survived, with the intention of continuing what was left over in life."
It sounds as though the story may have potential. One of the great tools of horror genre or any genre for that matter is the use of the 'ghost,' the even from the past haunting the hero. You have it, smacked dab in the middle of you're premise, great. Like I said, this is great tool, the ghost which sets of a necessary chain of events that the story can grow out of.
First, obviously, is the ghost itself that haunts the hero in whatever fashion. Secondly, the ghost creates the fear that boars a defense mechanism that hinders the hero in their approach to life. Lastly, if all goes according to plan, the hero will have the opportunity to learn and grow, or express some sort of real character development. Thus, the ghost creates the fear which creates the need which creates the opportunity for growth. Like I said, this is a great tool, but not without it's pit falls.