Okay, so I think there's some confusion here that I can clear up. 'Everybody Makes Mistakes' isn't a widely known published novel. I searched pretty thoroughly because the title felt familiar, and I finally placed it.
It’s the title of the first chapter of the 'Mistborn' series by Brandon Sanderson, specifically the first chapter of 'The Final Empire'. The prologue is called 'The Survivor of Hathsin', and then Chapter One is titled 'Everybody Makes Mistakes'. The main character introduced there, and for the whole series, is Vin, a street urchin who gets recruited by the crew leader Kelsier.
So if someone is asking about the main character of a book with that title, they're almost certainly referring to that chapter and, by extension, the novel it belongs to. Vin's the heart of the story—her journey from a terrified, distrustful skaa to a Mistborn who learns to trust and fight is incredible. It's a classic case of a memorable chapter title being mistaken for the book's name.