Change Daurama Daura's Son at 867 start to be of her house.

[Maimed_Dan]

Daurama Daura begins the 867 start in a matrilineal marriage, however her son and heir, born of that union, on that start date, does not begin of her house but of her husband's. I imagine this is not intended, and makes the 'Mother of Us All' achievement needlessly complicated.

 

[Less2]

You get an event almost immediately to change his house to yours. Other options include switching to female preference and having your sister be heir.