My Lady Jane by Brodi Ashton

The comical, fantastical, romantical, (not) entirely true story of Lady Jane Grey. In My Lady Jane, coauthors Cynthia Hand, Brodi Ashton, and Jodi Meadows have created a one-of-a-kind fantasy in the tradition of The Princess Bride, featuring a reluctant king, an even more reluctant queen, a noble steed, and only a passing resemblance to actual history—because sometimes history needs a little help.
At sixteen, Lady Jane Grey is about to be married off to a stranger and caught up in a conspiracy to rob her cousin, King Edward, of his throne. But those trifling problems aren't for Jane to worry about. Jane gets to be Queen of England.
Like that could go wrong