Wendy doesn't ever have an excuse to dress up, so she dressed up nicely and did her hair and all that. But unless someone dedicates themselves to talking with her, she turns in early and gives up on ever finding anything fun or nice about Christmas parties.
Lenore puts on a dress and tames that ridiculous hair of hers, and goes to the party with Alec. Like probably most of her other classmates, it does get a bit weird/boring after a while when all the adults are drinking so after a short while Alec and Lenore disappear to procure and drink alcohol somewhere not where adults are.