The Ebb Tide by Beverly Lewis and published by Bethany House Publishers.
As an Amish teen, Sallie thought her dreams of seeing the world were out of reach. A more attainable opportunity arises when she is offered a nanny job at a well-to-do family’s summer vacation home in Cape May, New Jersey. Sallie’s parents allow her to go, only when she promises to return to complete her baptism preparations. During her free time on the weekends, she meets a young man. Soon she wishes she did not make a promise she is no longer able to keep.