I haven't figured out where all my defaults are from yet, but I will add to this when I do.
Eyes: All my Sims are using callistra's defaults of La_exotique's Just Reflect eyes.
Skintones: I use the Dermalicious defaults. I also use the in-between tones and have geneticised them myself in SimPE.
Maternity wear: My Sims' maternity wear defaults are by engram_au. For more variety, I also have these default replacement meshes from MTS.
Homework: Yes, I'm that nitpicky that I use replacements for the homework books! You can get them here.
Books: I use these awesome covers and swap them around a lot, so I can see lots of variety in my game.