Mr. Roosevelt's Confidante by Susan Elia Macneal (Maggie Hope series Book 5)

This is the fifth installment to the Maggie Hope series

Summary
-December, 1941. Pearl Harbor, the largest Navy base in Hawaii, has been sneak-bombed by the Japanese Imperial Navy. Lives are lost and at risk. Prime Minister Winston Churchill has arrived in the US to negotiate with then President Roosevelt about the US entering the war. Maggie poses as Churchill's typist, which she has great experience with and once again, gets wrapped up in a mystery.

-One of Mrs. Roosevelt's aides disappeared, only to turn up murdered in her apartment, her death made to look like a suicide and a note left behind blaming Mrs. Roosevelt for making inappropriate sexual advances. All of this to try and undermine the President and cost American support in the war.