Every few days I go through my screenshots folder and choose the ones that stand out the most, and save them in a folder on my desktop (I play generationally, so I tend to have 1 folder for each heir sim), and then I also have started making a powerpoint of my sim story. So the first slide for each generation I have a big picture of that sim (usually together with their parent), and then a list of key facts about their life, where they lived, who they married, what job they had, how many children etc. Just things to help me remember the key things, and then I have a slide for pictures of their childhood, a slide for adulthood, and a slide for family photos so I can see how the family has changed from them being born to having a family of their own.
And then I do this for each new generation.
It means that now I can go through all the folders if I want more in depth memories, but if I go to the powerpoint, I can get a recap of all of my sims through 30 different generations and I love it! (If you do it regularly it doesnt feel like such a huge undertaking).
