Then, delete the "fictious father" of the child. Select the genuine father, right-click and pick the menu item Link as Parent. Move the mouse over the family of the the child. Voilà.
unfortnuately in psychiatry we have these very hard and sad topics as mentionned above. I tried to represent this situation linking a parent with one of his child as mate, but the result is not satasfying graphically speaking.
Has anyone an idea for a procedere in actual genopro, or as a future new feature ?