I'll help her out.
After I finished that 14 book saga, I wanted something light - at random. So, Discovery of Witches is book one of three. It is starting to remind me of Outlander in several ways - but the plot lines are different. It weaves solid history (author is an actual historian), and both myth and science history, into a romance between a witch and a vampire (yes, shoot me now) into part occult action novel, some deep research into 16th century British wiccans, and evolutionary DNA (Darwinian) concepts, alchemy etc with a heavy dose of how political things were in that century and how political the Catholic church was then. Old gods, new gods... echoing the GoT theme, too.
If it were one-dimensional, I wouldn't be so sucked into it, I think. It connects a whole lot of specialized knowledge areas into a story, that isn't slow anywhere that I've found.