Who is Herminia from Dreaming in Cuban and what is their importance?

Herminia is Felicia's best friend, they meet one day at age six while Felicia is picking up seashells on the beach. Upon hearing that Herminia has shells in her house that signify the future, Felicia, who has been forbidden to bring shells in her house at all, begs Herminia to save her. Herminia eventually does and they remain true friends for the rest of their lives.