Ok, I found the solution whitout using console (better for console versions right ^^).
So the problem is coming from a bad placement of brelyna maryon at the begining of the script.
So the key is to make here move before starting this mini quest.
To do so, the easy way is to use the first shout, will make move the girl, without starting a fight between you and her.
When she will get back to her normal position IT WILL WORK !
Good day !