Kristen Williams’s existence began when she was born into the Williams family of TS2’s Veronaville, according to the snapshot I have from when the family was created, this was in November 2011. Her parents (Carl and Melanie) and two older siblings (Jason and Natasha) were CAS-created, so she was the first in the family to ever exist as a baby. She went on to have 11 children, 2 of them were adopted and she had 3 sets of twins. The 3 oldest she had with 2 fellow tourists at the Three Lakes destination, and the others with her husband Forrest Haven.
I’m currently playing this family in TS4, this time around I started further up the family tree so Kristen’s parents (and grandparents) were born in-game and were childhood friends. The Williams family lives with Carl’s mother and his niece (who both happen to be named Charlotte). Kristen’s currently a child and only time can tell whether the “Forrest Haven” of her life will be the actual Forrest Haven or someone else.
This is Kristen now:

I honestly miss the TS2 Kristen but I do have backups of the whole sims folder from the time my old PC started acting up, so I could potentially revisit her.