So I just arrived to this cave and instakilled her, then proceeded to stomp the draugr and found out there were no levers to carry on. Found here that I need a key from her, so I looted her corpse, where I found only 3 potions, clothes and a dagger, but no key. Reloaded afterwards and saw that she was talkable and started to help her. However, this isn't listed as a possible bug, could it be part of a recent unofficial patch?
I will see if I can get through the dungeon this way, hope it doesn't glitch further...
First off, you cannot get through either of the doors if you kill her. You can do any of these things to continue the quest:
1: Load an old save from before you killed her, and wait until she gives you the key to kill her again.
2: Open up the console, by default activated with the '~' key. Click on the door. It should flash some seemingly random letters and numbers. Ignore those. Now simply type 'unlock', press enter, and leave the console, again using the tilde key. The door should be unlocked, but I haven't tested this personally.
3: Do the console thing. Type 'tcl' into the console, and press enter. Then, close the console, fly through the bars, and use 'tcl' again. This particular method, however, will skip a little more than half the dungeon, so I don't recommend it, just for the challenge's sake.