Further info. on Lucy Sandridge.Info. indicates Lucy has an uncle Hastings Sandridge.My best guess is that the Seamands, Sandridge, and Keaton families are all intermarried - so data indicates.
Therefore: Lucy Sandridge could be the dau. of Stephen Sandridge with middle name taken from Keaton relationship.Lucy Keaton could be a separate person (they have separate birthday and marriage dates to separate individuals) the dau. of a male Keaton and a female Sandridge ie: cousins.
I am continuing to check the Hastings Sandridge connection - should be grandson of William Sandridge.