Who is Eva Kay from The Buddha of Suburbia and what is their importance?

Eva is a suburban wife who takes an interest in Haroon because she is attracted to the exotic and they share an interest in Eastern Philosophy. Even before her relationship with Haroon blossoms into a full love affair, she also takes an interest in Karim. Eva and Haroon's passionate affair leads to the dissolution of Karim's family, yet her maternal role leads Karim to a close relationship with her. She looks out for Karim, in some ways more than her own son, Charlie.