First time posting here. I hope I have chosen the correct forum.
I have a very interesting issue in my family tree. In my direct family line, my grandmother was raised as the daughter of her grandmother, and as the youngest sister in the family, with an older "sister" who was actually her mother. I'm sure this is a common enough situation. But, the unusual twist is that her bio father is the uncle of her bio mother. All of this is proven in multiple ways using DNA, on both the uncle's and the niece's side.
My problem relates to the way this should be properly shown in my tree. I'm going to put some names here so it is clearer.
Mary Docksteader (1841-1923) is both my second and third great grandmother. Mary McNichol (her daughter, 1859-1942) is my second great grandmother. It is the son and daughter, respectively, of these women who were the parents of my grandmother.
I have merged the two Mary Docksteaders, so that the same individual holds two roles in my tree. But now, I have weird things happening where a person who is actually my fourth great grandmother is shown as the "mother-in-law of 2nd great-grandmother".
Is there a proper way of handling this in a family tree so that the relationships are correct? Should I create two Mary Docksteaders with different roles but the same data?
Thanks very much in advance.
(Ottawa, Ontario, Canada)