Dark Witch by Nora Roberts

Iona Sheehan has just arrived in Ireland. She knows that she's special, that her family has powers.

Image linked from Goodreads

She is to be the third, the witch that will help to put away and ancient Big Bad for good.
The Big Bad is delighted that she is there. He sees her as the weak chain in the chain that could take him down. Of course, Iona is tested.
At the same time, she falls into lust with her new boss, the owner of a local stables, Boyle McGrath and has to juggle her burgeoning powers with the feelings that she has starting for this rough man.
Perhaps it's not fair to judge Nora Robers against herself, but this is just not one of her most stellar books. It doesn't have as much depth as some of her other books and just seems to skim along. The bad dude isn't as well developed and neither are her characters. Of course, she is introducing six people and all of their backgrounds and that can be hard to do but I feel like we learned about them all on a superficial level and didn't really get to know our hero and heroine or their relationship.
So far, not as good as the Sisters Island trilogy but I am always willing to keep an open mind.