Duchess by Design by Maya Rodale

In Gilded Age Manhattan, anything can happen…
Seeking a wealthy American bride who can save his family’s estate, Brandon Fiennes, the duke of Kingston, is a rogue determined to do the right thing. But his search for an heiress goes deliciously awry when an enchanting seamstress tumbles into his arms instead.

…and true love is always in fashion
Miss Adeline Black aspires to be a fashionable dressmaker—not a duchess—and not even an impossibly
seductive duke will distract her. But Kingston makes an offer she can’t refuse: join him at society events to display her gowns and advise him on which heiresses are duchess material. It’s the perfect plan—as long as they resist temptation, avoid a scandal, and above all do not lose their hearts.