Never Dies The Dream by Margaret Landon

'An unmarried woman missionary in Siam incurs criticism and suspicion when she shows marked favor to an unfortunate American girl at the mercy of the Orient; later, when she risks her own life by isolating herself to nurse Angela through typhoid, she loses her own position. Neither the author nor the heroine of the novel admit the faintest tinge of lesbianism to the relationship, which is full of warmth and selfless sacrifice, and India angrily denies the accusation when it is made; but the high emotional intensity of the whole story bring it well within the boundaries of the field and place it high on the list' ~ Marion Zimmer Bradley