Tide and tempest / Elizabeth Ludwig.

Enhanced descriptions from Syndetics:

Two years ago, her fiance perished
during their voyage to America.

Now she discovers it may have been murder...

Dreaming of a better life, Tillie McGrath leaves Ireland behind and, with her beloved fiance by her side, sets sail for America. But when illness robs her of the man she holds dear, she's left alone with only a handful of tattered memories. While forging on proves difficult, Tillie soon finds some new friends at her New York boardinghouse, and begins pursuing a new dream--to open a home for orphaned children.

Despite two years passing, Captain Keondric Morgan has never forgotten the lass who left his ship so heartbroken. When a crewman's deathbed confession reveals her fiance's demise was the result of murder, the captain knows he must try to contact her. But his attention draws the notice of others as well--dangerous men who believe Tillie has in her possession something that could expose their crimes. And to their way of thinking, the best way to prevent such an outcome is to seize the evidence and then hand Tillie the same fate as her na ve fiance.