Who is Mica from Songs of the Humpback Whale and what is their importance?

Mica is a waitress at the 24-hour Blue Diner in Boston, Massachusetts, takes Oliver to her apartment to rest. After hearing his story about his runaway wife, Mica urges Oliver to go to her and tell her how he feels. At Mica's apartment, Oliver sees the news about a stranded humpback whale near Gloucester and heads there instead.