Welcome back Sky!
anyways, I also think Shirley was happy in that scene, being her optimistic self. She even said she was happy just because she got to be with Lelouch in the end...she also got to tell him how she felt, which meant a lot to her. The poor girl was so confused then, but she knew one thing for sure: She loved Lelouch, and she wanted to be truthful to him even when no one else would be. The only thing I wonder is how might she have felt to see him start to break down like he did? I could see that upsetting her...but she did manage to keep a smile on her face that whole time...
Also, I dont know if this is true or not since I read it on Wikipedia...
...but apparently Shirley's design and name are references to Anne Shirley from the anime Anne of Green Gables. can anyone confirm this?