Who is Tsige from Cutting for Stone and what is their importance?

Tsige is a prostitute. She lives across the street from Missing Hospital throughout Marion's childhood. When Marion is a teenager, Tsige arrives at the hospital clutching her dying baby. Marion stays with Tsige, offering her support after the baby dies. Tsige never forgets Marion's kindness, and she prays for him every night. Later, Marion is later reunited with Tsige at The Queen of Sheba in New York.