First cousin marriage duplicates all descendants

Question

Ugh, so I found this problem somewhere around 10 generations back. I found 2 brothers whose children were married, but working up the tree, I can't add an existing person on the tree as a sibling, so I tried joining one parent for each brother as partners already on the tree, but that duplictes everyone who came after, including me. How do I do this? Thanks for any help.

Answer 1

You can´t add an exisiting person on a tree as a sibling but two cousins have a common set of grandparents. So, create the father of each partner and join them by assigning them the same parents.