By The Light Of The Setting Sun by Laura Rollins

Amidst autumn leaves and rumored ghost sighting, Alex must choose between duty to his family or the devotion of his heart.

Alex Drake, Earl of Linsfield, has spent years ensuring his brothers’ futures. But an uneasy feeling tugs at him. His young step-sister, neglected by her father, is in need of his care and protection. Alex determines nothing will stop him from helping her—not the girl’s father who resists all attempts to help, nor the beautiful and engaging lady who keeps crossing his path.
Lady Elizabeth Vaughn faces a dire choice: support her family, or risk losing everything they hold dear. Her father’s health continues to decline, despite the efforts of Bath’s finest physicians. After four failed London Seasons, marriage remains an elusive salvation. The family curse is to blame, according to her aunt—it states no lady from their lineage shall marry for love. But if Elizabeth doesn’t marry, what other options are there?
An unconventional meeting between Adam and Elizabeth sparks an instant friendship. As they help each other find solutions, their hearts soon become entwined as well. Yet, when forced to choose, how can Alex pick between saving his step-sister, or following the desire of his heart?