I think what is one the skyrim wiki, is what happened to me.
- If Brelyna's casting path is obstructed by an object other than the player, he or she will be STUCK PERMANENTLY waiting for the effects to wear off.
- Solution: (PC Console) enter "setstage MGRappBrelyna01 30" in the gaming console to force the quest to the next stage, where the spell has worn off.
Since i have a 360, i tried the whole become ethereal thing, but it still hasn't fixed this bug. She keeps saying that she needs help if i can spare the time, but when i talk to her, the options continuing this quest are not on the list of possible discussion topics.