Most Genealogy software vendors decided to follow the model that professional genealogists use. The basis is a family group sheet, that includes the father at the top left, the mother at the top right, and the children below.
The database structure then chosen is to have records of two types: Individuals and Families. These are exemplified by the GEDCOM standard which is used to transfer genealogy data between programs.
Then they use what is called a lineage-linked data structure. This structure has two connections:
The Individual will link to the family in which they are a husband or a wife (a FAMS link) and the Family will link back to the two individuals (a HUSB and a WIFE link).
The Individual will link to the families who are their parents, either blood or adopted (a FAMC), and each Family will link back to their children (CHIL links).
Once you develop your program, make sure it will be able to read and write GEDCOM.