New California starts in 2260 and FO3 in 2277. However, the PC is nineteen years old at the start of the main game, meaning the PC was born in 2258 in Vault 101, two years before the start of New California. This would make it a little hard to play as Dad/Mom.This doesn't fix the problems, but to be fair your character wasn't actually born in Vault 101, no matter what Ron Perlman says. You're born in the Jefferson Memorial, and your first 'real' memory of the vault you're already able to walk so you're almost certainly over 1 year old.