Yes, it had been a waste of her time. Narcissa needed to learn to pick up on when her guest was laughing at her and not with her.
"That was very kind of you. Well, I'd love to be a help, but my schedule's pretty much packed. I was thinking I might just make a donation." And that way half of my money won't go towards streamers and balloons or whatever else ridiculous things you would get for such a party.