The book's jacket is nicely illustrated with a portrait of ... wait just a minute! That's the wrong Jane!
The cover image comes from a well-known portrait of Jane Seymour, Henry VIII's third wife. To the right is the full-length portrait.
I can just imagine the cover designer's thought process. "Hmmm, no Tudor-era portraits have yet been identified as Jane Boleyn. What am I going to do about this cover, then? Wait ... here's a portrait of Jane Seymour. Close enough! We'll just focus on the dress and omit her head, and no one will ever know the difference. Besides, headless woman covers are all the rage now."
But as Daphne noted in her comment at Reading the Past, the people most likely to read a book about Jane Boleyn are also likely to recognize the portrait on the cover.
This is not the first time I've spotted the wrong woman on a book cover. Look at this one, for example:
This edition of The Princesse de Cleves, a novel of love and intrigue at the 16th-century French court, features a portrait of Anne of Cleves on the cover. Except ... the story isn't about Anne of Cleves (another of Henry VIII's brides).
The novel is about the exploits of a woman who marries a "Monsieur de Cleves" but later falls in love with a handsome duke at court. Did this cover's designer just Google "Cleves," come across Anne's portrait and slap it on the book without researching who she was?
Here's a puzzling choice of a cover image for Alison Plowden's Tudor Women: Queens and Commoners.
The woman on the cover may have married two Tudors (Arthur and Henry, sons of Henry VII) but she wasn't a Tudor; she was Spanish. Yes, this is a portrait of Katherine of Aragon, Henry VIII's long-suffering first wife.
Technically, I guess you could call Katherine a "Tudor woman" since she married into the family (although she identified herself with Spanish interests rather than English ones her whole life.) But why use Katherine when portraits of many other Tudor women exist: Margaret Beaufort, the matriarch of the family; Henry VIII's two sisters, Margaret and Mary; or the two Tudor queens, "Bloody" Mary and Elizabeth?
Note to book designers: Readers notice these kinds of things. It would behoove you to do a bit more research before putting a portrait of a historical figure on a book.