Same person.
(Anna)belle gave her age as 57, when it should've been 60. Three years isn't much for a person her age. Her only child, David Ives Bushnell, Jr., aslo appears on the 1920 census as a resident of Charlottesville VA.
The Johnston family lived in Mason County KY in 1850. Her older brother James was born in KY in 1857, but can't locate the Johnstons in 1860. When he enrolled in the U S Navy in 1861, John Vincent Johnston was stated to be a resident of Cincinnati OH.