In the short story "The Canterville Ghost," the young Virginia helps the ghost find peace and move on to the Garden of Death. In the story, she is the only character who listens to and heeds the words of the ghost, while her parents just try to ignore him.
The ghost tells Virginia that she must do three things to help him pass on to the other world, things he can't do himself. She must weep for him, mourning his death with tears he doesn't have, she must pray for him, interceding with faith he doesn't have, and she must go with him to beg for mercy on his behalf. She does all these things, following him to the Garden of Death and asking Death for mercy on the ghost, who is granted peace and allowed to pass on.
Virginia is then able to return to her home and the family lives in peace.
At the end of Chapter Five, Virginia helps the ghost to rest eternally in the Garden of Death. She does this by accompanying him through a gap in the wall of the Tapestry Chamber and into the "black cavern." Though Wilde does not reveal the specific details of what Virginia does, we can infer what happened from the following four lines of the prophecy on the library window:
When a golden girl can win
Prayer from out the lips of sin,
When the barren almond bears,
And a little child gives away its tears.
In other words, Virginia prayed with the Canterville ghost for his redemption. She also cried to express his sorrow for all the crimes he has committed because he is physically unable to shed tears.
Evidently, Virginia is successful in her efforts to help the ghost and so the prophecy is fulfilled. In return for her assistance, she receives a box of jewels from the ghost and the family are able to bury his body.