in my co-op run i'm currently doing with a friend, at the end of act 2 we invited almira to the boat and she was on the lady vengeance when we departed for act 3
however, when we arrived at the nameless isle she had vanished from the game
I had the same issue on my previous run and emailed Larian with a save at the end of act2, just before entering act3. You could try to do the same if you still have a save, maybe they can quickly fix it.
I have encountered this bug on 2 co-op playthroughs now. I thought it might be because the tablet never dissapeared from my inventory, so before leaving I pickpocketed her and put the tablet in her inventory.
