Here's the info on book three and four of The Dashkova Memoirs.
Birds of Prophecy
http://thomaskcarpenter.com/2015/05/26/birds-of-prophecy-the-dashkova-memoirs-3/

Katerina Dashkova must die.
When Warden Simon Snyder seeks Kat’s help to solve a bloodless murder, she becomes entangled with a prophecy that predicts her death on the Winter Solstice. The investigation turns an old friend into a dangerous enemy, complicates loyalties, and creates a mystery so deep that Kat will have to expose herself to ultimate betrayal to solve it. Even if she does, the question remains: Can she save Philadelphia from an ancient evil?
The Franklin Deception
http://thomaskcarpenter.com/2015/06/13/the-franklin-deception-the-dashkova-memoirs-4/

When Thomas Jefferson’s longtime companion is murdered with dark magic, Katerina Dashkova and Ben Franklin must find the killer before the war-hungry Federalists learn the truth and use it to maneuver America into a war with Russia. Unfortunately, the unknown assassin isn’t the only one causing trouble: a certain rusalka with a magical hold on Kat’s future has made an impossible demand that will test her loyalty to her new country to its very limits.
The books can be found on Amazon in ebook or paperback form. :)