Queen Among The Dead by Lesley Livingston

I'm a sucker for Celtic lore so this book was a must read for me and should be for you as well. Filled with magic it's full of banshees, shapeshifters, and Druids.

Magic has been outlawed as dangerous by the King, but Eire is suffering without her wild magic running through her soil. Spells are being traded under the Kings nose and magic still used by those skilled enough and savy enough to stay hidden. Meanwhile the Druids are the only ones allowed to practice magic and are building a massive temple for Princess Neve's father. Never finds herself stuck between being what her father wants and being herself. Of following the magic that calls to her blood and the voice of her ancestor in her head slowly changing who she is. With the help of an outcast named Ronan maybe she can set to rights her kingdom and bring Eire back to life.