Louisa is in the LDS Ancestral File database with her husband and
children and it has her parents as William and Lucinda R. Slaughter,
(no maiden name given for Lucinda), died in Muscatine Co., Iowa,
same ages as Lucinda Matthews and William Slaughter here.
That and the combination of migration from Indiana to Muscatine County
make me pretty sure that Louisa belongs in this family.