Well, it looks like for some reason Karliah constantly has her Nightingale armor and helm equipped, I can't even remove them via console, they're not in her inventory, even after I disable the essential npc flag and kill her. Thus I'm unable to take a look at her face. Sadly my last save on this char is after I completed the quest line so I can't go back. Also, if I spawn her through console, no matter which ref id (or object id, I tried both) I choose, she always appears with that unremovable armor on. Looks like the only way to find out if it works for me is to start a new game and go through thieves' guild quests all over again. Another time maybe. Anyway thanks for help.