Who is The Laughtons from To Have and Have Not and what is their importance?

The Laughtons are tourists in Key West. They are drinking at Freddy's bar when Harry Morgan comes to finalize the charter with Attorney Robert ("Bee-lips") Simmons. James Laughton is described as a very tall, thin, wide-shouldered writer with glasses, a deep tan and close-trimmed sandy mustache. His wife wears her hair cut short as a man's and has a bad complexion.