I didn't see the 9/11 episode until last night. The tone of the show seemed pretty brutal, between the outright mockery of the Guidices by the rest of the cast and poor little Gia's tears.
It left me with the impression that, of course, it was all pre-planned. I don't know for sure if Gia wrote that sad song or not, but I'm sure she was told to sing it even if she did not want to. I think her tears could have been about that - and not about her worries. She knew she was expected to sing it, hated doing it, and cried during the performance. I'd cry to if I had parents who allowed a TV network to use me that way.
Her song to Milania was sweet, though.