D'oh! Looks like you're correct. I've read a lot of actual history about medieval England; I also recently read an historical fiction book called The Other Boleyn Girl. A lot of the facts in the book are correct...but apparently the Mary Rose being named for Mary Boleyn is fiction rather than history. The dates don't work -- the Mary Rose was built a decade before Mary Boleyn's affair with Henry in the 1520s.
Mary Boleyn