I'm glad Nadia confessed her secret to the public before she went into the house because it stops any speculation about her which the papers were bound to bring up, as they're always looking for the dirt on H/M's. Now we all know who she is, it's easy for people to say "Yes, I know she was a he, I could tell", personally I wouldn't have guessed, not straight away anyway.
The fact she hasn't told the H/M's yet is interesting, why?, because at this moment they are treating her the same as any of the other females in there, for who she is, not because of her gender, they see her as Nadia.
When they find out will be interesting, to see if their opinions and attitude change towards her, I suspect they will, particularly from the men and in particular from Ahmed, after seeing his views on gays in his interview for his application, despite seemingly getting on with her at present.