Penny doesn't bother to get ready with everyone. Most of her cabin isn't really like that, anyway. She dresses for the dance on her own and makes her entrance without anyone having seen her before or with anything she has as sh enters the dance. Though the basic mask might be recognizable, Penny did her best to finish it out of sight of anyone but Mr. C-B. She's wearing a sparkly dress, nothing too fancy but nothing too casual, either.
Penelope
She's actually feeling kind of hopeful.