The Viscount’s Daring Cinderella by Hayleigh Mills

Orphaned and unloved by her envious cousins, Lady Beryl is determined to find her own match while enduring a season of chaperoning her spiteful cousin. Meanwhile, Lord Theodore Godwin, unexpectedly becoming Viscount Bowden, revels in a life of hedonism, shunning marriage despite his new title and the care of two nieces.
Hiring Lady Beryl as a governess, he continues his libertine ways. As they both pledge to propriety, Theodore unexpectedly finds himself irresistibly drawn to her. Beryl, caught in a whirlwind of love and passion, soon faces the heartbreaking realization that she may never be Theodore’s wife.