I cant find the first mate, shes dissapeared. you need to tie her down to one location such as in the tavern or in the boat and perhaps make all your crew spawn at your ship whenever you sail from on place to another
i re-installed the mod and for some reason their all staying in the ship this time so maybe it just loaded wrong, i thought it would be cool if your not too picky to be able to hire a random pirate by just talking to the first mate