There was one point when she was walking across that bridge thing near the audience and it was quiet, then you could hear her mic being switched on because the crowd noise suddenly popped up.
She was so far away from the audience why would you hear them?
I'm not sure if she lipped some parts, but even if she did, what's the big deal? She has the best vocals out of all the pop girls, we know that already. Plus she's the best performer.