nixfiles-emily/config/users/emily/default.nix

{ config, pkgs }: {
  users.users.emily = {
    isNormalUser = true;
    shell = pkgs.zsh;
    extraGroups = [ "wheel" ];
    openssh.authorizedKeys.keys = [
      "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIA/+iN407+HsfHbbC3tfdA8Yf4TZ08qXQMb4tb/SDAs+ emily@card"
    ];
  };
}