The death record for Martha E. Preston (28 July 1941) lists her father as Amos.
In 1860 & 70 Amos Byrd's family is in Greene County. In 1860 Martha has a brother, James (age 5). In 1870, James Bird (15 OH) and Charles Preston (19 KY) live in the Haverstick household.
They are both listed as white, but I'm told that the 1870 census records that we see on Ancestry are actually a transcription of the originals.
There's also a family tree on Ancestry that lists Levi Haverstick's wife as Amanda Bird, and another family tree for Amos Byrd that lists a sister Amanda.