Who is Celestine Amabo from Diamonds in the Shadow and what is their importance?

Celestine Amabo is Mattu and Alake's mother. Her real daughter was killed by a child soldier during the civil war, thus, Celestine refuses to adopt Alake as her own. Determined to make life work in America, Celestine is the primary breadwinner for the family, as well as her husband's caretaker. In the end, she also comes to love and accept Alake as her own.