Genetics is my favorite part of the game. (Note, any sib sets do not have any first born syndrome repeats)
Raine + Adagio Hart = Hazel Hart. Hazel is a third-gen sim as both her parents were born in game and have their own set of parents. Hazel inherited her mother’s eyes which originated on a CAS sim that ended up mothering Raine.
Elm + Harmony Calhoun = Nicholas Calhoun. Nicholas is Hazel’s cousin as Harmony and Adagio are siblings. Nick has most of his father’s face in general including the eyes that originated on Elm’s paternal grandmother.
Adriana + Pryce Cosgrove = Melinda Cosgrove. Melinda’s genetics favor her father, even though she has the same eye-style (Maxis default replacement) as her mother she does have brown-colored eyes like her father. The thinner lips and wide mouth originate from her paternal grandmother.
Lawrence + Noelle Orbinson = Evelyn Jane Orbinson. Evelyn Jane is basically a mini-me of her mother. Her custom green eyes are a strong genetic trait inherited from her maternal grandparents who both had them as well as her mother.
Jonas + Cheyanne Wellington = Amelia Wellington. Another case where the daughter is a mini-me of her mother. There are hints of Jonas by way of her lower jaw and lips but her eyes and nose area are purely inherited from her mother’s structure.
Looking at Lawrence Orbinson and Jonas Wellington, they are first cousins (their parents were fraternal twins) and you can see some similarities inherited from their shared grandparents, the cheekbones, pouty lip shape, and triangular nose are a common inherited structure between them.
Here is Amelia Wellington’s sibling set. Her and the guy on her right are twins and she and her two brothers share a lot of similarities. Her younger sister, Piper, takes more after their father, Jonas, above.
Here is the Calhoun sibling set. The last two are twins. I think they all strongly resemble each other and have an even blend of their parents’ features instead of any favoring one over the other in inherited genetics.
The Louis sisters have a variety of custom genetics to pull from as 4th-gen sims. They all inherited their father’s custom skin tone, the eldest inherited her maternal grandmother’s eyes, the second and third inherited their paternal grandfather’s eyes, and the youngest inherited her paternal grandmother’s eyes.
From that Louis sibling set, here’s a three generation panel showing how the youngest resembles her paternal grandmother a great deal. While the third daughter in the set looks the most like her father, the man in the middle.
This three-generation panel shows how genetics pass from a grandmother to her grandchild. Her son had an affair with a woman with bright blue eyes which is why his daughter has those.
A final three-generation panel shows how skintone and eye-shape passed to her from her paternal grandmother. Her golden cc eyes are an exclusive gene passed from her maternal grandmother.