Alice Drablow was the older sister of Jennet Humphry (Later known as The Woman in Black). She died at an advanced age which then brought Arthur Kipps to Eel Marsh House.
Before Her Death
When Alice Drablow's husband Charles Drablow (His name is in question) had an affair with her sister, Jennet, Alice incorrectly blamed Jennet and had the authorities take the resulting newborn child from Jennet so that Alice herself could adopt him to spite her sister. Alice excommunicated her sister from the boy and the rest of the village, right up until the point where Jennet threatened violence if she could not see her son - named Nathaniel.
However Alice eventually allowed Jennet to see her son only if She did not tell the young boy that he was her son. So Jennet was introduced to Nathaniel as his nanny.
On the 18th of October 1889, The pony and Trap that had Alice, Nathaniel and the horse driver on it went into the Marsh. Only Alice and the horse driver survived while Nathaniel drowned. Her sister Jennet who was watching from the nursery window blamed Alice for his death because Alice stood there and didn't do anything to save the boy. A month Later Alice found her sister hanging from a beam in the Eel Marsh house nursery. As well finding "You could have saved him" written on the wall in Jennet's blood.
The Haunting
After Jennet's Death, It is theorized in many of the adaptation of the book that Alice was driven insane by the haunting by her sister. Throughout the rest of her life she was haunted and tortured by her dead sister. Alice tried everything to make it stop but it wouldn't.