I heard last Saturday on French television that there would be a secret room in the house and that she would be revealed very soon on the occasion of a big event.
It said:
"Même si la maison de Big Brother est trés petite, elle cache de nombreuses surprises comme une pièce secrète cachée derrière les murs de la maison. Selon les rumeurs, elle servirait Ã* contenir des candidats pour un grand évènement trés bientôt"
In english:
"Even if the Big Brother house is very small, she hides surprises as a secret room, behind the walls of the house. According to rumours, it would serve for containing housemates for a big event very soon"
I like it !