Ruth Fielding at Lighthouse Point or Nita, the Girl Castaway

Popular children's novel first published in 1913, part of the Ruth Fielding series. Accordiing to Wikipedia: "Alice B. Emerson is a pseudonym used by the Stratemeyer Syndicate for the Betty Gordon and Ruth Fielding series of children's novels. The writers taking up the pen of Alice B. Emerson are not all known. However, books 1-19 of the Ruth Fielding series were written by W. Bert Foster; books 20-22 were written by Elizabeth M. Duffield Ward, and books 23-30 were written by Mildred Benson.”