The Mayflower Ciphers (Andrietta Sloan Adventure Series Book 1) by Rae Davis

 The Mayflower Ciphers (Andrietta Sloan Adventure Series Book 1) by Rae Davis
https://www.amazon.com/Mayflower-Ciphers-Andrietta-Sloan-Adventure-ebook/dp/B0792BC65Y

Andy Sloan, researcher and finder of rare artifacts,  has been hired by Dr. Porter Gaven to acquire some diaries written aboard the Mayflower by pilgrim John Alden. She steals the diaries from their dead owner and discovers ciphers and a valuable treasure inside the hollowed out pages of Volume II. She is chased, shot at and kidnapped before she can get the diaries and the treasure back to Dr. Gaven.