The descendantsee software has a focus on the blood line of the prime forebear.
The non-descendant birth-parent of a descendant child is referred to as a spouse and is coverred under that section.
I is not intended that a non-birth parent be recognised as a parent of a descendant child, only the genetic parents.
The software does cater for non-blood related persons to be "Grafted" into the records.
The principal graftees intended are Adopted Children, Foster Children and Step Children recognised by a descendant.
This is recognised and visible in the "lineage Sequence".