i finished the shivering isles so i went straight back to cyrodiil, as soon as i passed through the gate i noticed a dark seducer named adeo had followed me. if i try to talk to her it says "I HAVE NO GREETING" and there is a glitch top left of screen. she follows me everywhere which is really annoying because i cant make her stop. im trying to do the dark brotherhood quests but she keeps getting detected. i tried going back to the shivering isles but she remains in cyrodiil then follows when i get back. its the complete edition through steam and the only mod im running is qarl's texture pack

Do you recall having any problems completing http://www.uesp.net/wiki/Shivering:The_Helpless_Army the first time? Assuming the quest is finished, and you don't mind losing her; open the console (~), click her, then type without quotes "kill". If none of the above fix the problem, then you're in trouble