With the exception of my first sim Alycia, all my sims have been "born" in game, their features have been generated by the game (**alien disguise being the exception to this... their "normal or disguised" appearance is completely selective") and their traits have been generated by a randomizer rather than selected by me. Of course, when I get my sims out to meet someone, they can be a little selective in the "get to know" and avoid those hot heads though I do mix it up on occasion just to keep things interesting... try raising a family with someone who hates kids!! I may change hair style or tweak the colour on occasion, and I do use a life mod that adjusts the numbers of days on long lifespan as I find the normal life span too short, but traits are not open to change :) I must say, so far, I've been lucky with some attractive sims :)
Legacy Succession Laws
Strict Matriarchy
The Founder must be female. Only girls are eligible to be named heir. Male children cannot, under any circumstance, ever be the heir to the next generation.
Strict Traditional
To be eligible to be named heir, a child must be naturally born from their previous-generation parents and be able to trace an unbroken bloodline back to the founder. Adopted children may never be named heir.
First Born
The oldest, by order of joining the family, eligible living child is named heir.