Merely a Marriage by Jo Beverley

As England mourns the death of Princess Charlotte, Lady Ariana Boxstall has another succession in mind. Her brother, Norris, is a strapping young man, but he s also happily unmarried and childless. Norris agrees to take a wife on one condition: that Ariana take a husband first. Although she realizes she risks a lifetime in a loveless marriage, for the sake of her family, Ariana accepts his challenge.

When the Earl of Kynaston met Ariana eight years ago, he broke her heart. Since then, his own heart has been broken, and he s sworn off love…until he sees Ariana all grown-up and his resolve is threatened.
Could Ariana s bargain with Norris actually lead her to happiness? With real love on the line, she must win over the one man who refuses to be had.”