Bess Southerns is struggling to keep her family fed when a spirit visits and tells her she has the power to bless.

In Tudor England, where doctors are scarce, expensive and dangerous, a good healer can be worth her weight in milk and oats.

Bess latches onto her calling and becomes the best-known cunning woman in Lancashire. But even as she blesses children and horses and makes herbal brews to help women conceive, she is aware of the danger her new profession poses. The new Protestant church sees little difference between the goodhearted blessers known as cunning women and witches. If a child dies or an herbal remedy has unintended side effects, Bess could be burned at the stake.

American Mary Sharratt based her new novel, “Daughters of the Witching Hill” (Houghton Mifflin Harcourt, $24), on the Pendle witch trials of 1612, which officials documented extensively. Ten people were convicted, and nine — seven women and two men — were hung together.

As Sharratt notes in an afterward, the striking thing about the Pendle trials was that several of those accused in the trials freely confessed. Among England’s very poor, being a cunning woman was a source of pride.

Sharratt draws on the confession of the real-life Elizabeth Southerns to create her main character and also show how both the cunning women and their clients could see the power of miracles and curses in the world around them.

Bess lives through England’s shift from a Catholic to Protestant nation. By the time she meets her familiar spirit, the Virgin Mary statues, Latin prayers and folk festivals she grew up with have been banned and she is longing for a personal connection to a higher power not provided by the stark religion of England’s Puritans.

Sharratt tells her story through the eyes of Bess and those of her 15-year-old granddaughter, Alizon, who has reluctantly inherited her grandmother’s powers. She also weaves a compelling subplot involving Bess’ best friend, who turns to witchcraft to save her daughter from rape and then finds herself an outcast when the marauding gentleman dies.

American witch trials are usually presented as calamities in which innocent men and women are wrongly accused of having personal vendettas or political agendas. “Daughters of the Witching Hill” offers a fresh approach with witches who believe in their own power and yet, in many ways, are still innocent.