One of my all-time favourite Joan Smith books.
From the book blurb:
Ella Fairmont, as the anonymous Miss Prattle, has taken the Duke of Clare to task regularly in her gossip column. The duke, unsuspecting, includes Ella and her aunt in his week-long country houseparty. He has also included the blue-blooded Lady Honor, the strikingly beautiful Miss Sheridan, and the multi-talented Miss Prentiss. How could one “ordinary” young lady with a sharp tongue compete with three sterling debutantes?