And here is the final (for now) extended relationships guide!
The oldest kid in the Fyres household is Roger.
Roger’s parents are Brock Redmond and Sibohan Fyres, who randomly hooked up at some point.
Roger has seven half-siblings: Loretta (via Siobhan) and Brielle, Finn, Fiona, Hank, Harrison, and Phoebe (via Brock).
Brock and Maci are twins, so Maci’s four children (Elliott, Ginny, Isaac, and Nina) are Roger’s cousins.
Loretta is the second child in the Fyres household.
Loretta’s parents are Siobhan Fyres and Ricardo Tellez. Therefore her only half-siblings are Roger and Trinity, and she doesn’t have any cousins in the save.
Trinity is another easy one to explain–since she is Ricardo’s alien daughter, the only sims she’s related to in the save are Ricardo and Loretta.