That Lucy Gallemore married James Lukenbill in Morgan, Indiana on July 9, 1876. Sometimes on death cert, and SS apps, I have seen where there would be incorrect info given as parents. Most of the records I came across shows that Jessie was married to Lucinda Massey.
This is where DNA might help answer some questions. It is strange that 2 of the children would list their mother as a Gallemore. Maybe they knew the Gallemore family, or were related to them in some way. The mother did die young, so it is possible that they could be wrong on the maiden name. I could not find a death for Lucy/Lucinda Holder in Tx. That might help answer this mystery.