Who is Rhoda from The Waves and what is their importance?

Rhoda is a loner, who lacks in self-confidence. She sees herself as unimportant, a feeling that never goes away and eventually leads to her suicide. Rhoda was brought up by her Aunt, and there is never any mention of parents. Her upbringing has lead her to become an emotional cripple and even in intimate relationships, she is afraid to get too close..... even to Louis.