Narcissa Malfoy mainly passes with a mention in this book. Harry mocks Draco:
You know your mother, Malfoy? [...] that expression she's got, like she's got dung under her nose? Has she always looked like that, or was it just because you were with her? (13.89)
This visual impression that Harry has of Narcissa Malfoy suggests that she's snobby and really hard to please. It's pretty Slytherin-ish of Harry to use this against Draco, but on the other hand, Draco has just been insulting Mrs. Weasley. Once mothers come into a fight, you know it's going to get ugly.