In Pursuit of the Green Lion by Judith Merkle Riley

The unforgettable Margaret of Ashbury returns in the second book of the trilogy that began with A Vision of Light. Margaret, a resourceful midwife, is living with the insufferable relatives of her third husband, Gilbert de Vilers, known as Gregory. She is carving out a life for herself and her daughters despite the hostility and greed of her in-laws. But when Gregory is captured in France and held for ransom, Margaret knows she must take action'??her in-laws are too tight with money to be of any use'??so she teams up with her old friends Mother Hilde, the herbalist, and Brother Malachi, an alchemist on a quest for the secret of changing base metals into gold. Together, the trio plan to rescue Gregory and bring him back to London, where he and Margaret can start a new life away from his meddling family. And thus begins a wild romp across fourteenth-century Europe. Murderous noblemen, scheming ladies, truculent ghosts, and a steady stream of challenges plague the journey. Margaret will need not only her special gift of healing, her quick mind, and her independent spirit but the loyalty of her friends and the love of her new husband to carry them all safely home. From the Trade Paperback edition.

This book is part of the "Margaret of Ashbury" series.
Here are some other books from this series: