The Legend of Annie Murphy (The Cooper Kids Adv. Series #7)

In 1885, the Murphy mine struck gold. According to legend, Annie
Murphy killed her husband out of greed, but just before she was to be
hanged for the murder, she escaped. Now, a hundred years later, there
have been sightings of Annie Murphy’s “ghost.” The Coopers unwittingly
become involved in a mystery that finds them caught between the past and
the present.