Rosalyn's Ring — Alina K. Field

Done with grieving her losses, a late nobleman's daughter has fallen into a tidy spinster's life in London. But when one snowy Christmas Eve, a young woman needs rescue, she seizes the chance to do good -- and to recover a family heirloom that ought to be hers.

Irked by his late father's dreams of nobility, a newly anointed viscount has drawn the line at marrying a blue-blooded miss -- until he meets a provoking beauty with an upper crust manner, a larcenous streak, and enough secrets to rouse even his jaded heart.
And when more mysteries swirl around the lady's lost inheritance, he is just the right man to help her uncover the truth.