I have not tried the coop yet but I think if you choose the multiplayer option then one of your friends can join you during the character creation on make their own character (is it correct?)
It's this. In Singleplayer, the host creates both characters: appearance and build. In multiplayer, each player can do their own appearance and build.
P.S. Larian: The local chat MUST, MUST be visible during multiplayer character creation to help players coordinate their builds. They're not always going to be side-by-side or have a Steam overlay. It's vital that there be a way to coordinate.
