Did her fellow MCs realize the extent of her interior torments?

No. Her closest collaborators did not know. They saw the fruitfulness of her work. They saw her joy. They saw her prayer. They had no idea of the intense interior trial of her heart. They did not know that her intimacy with Christ had been veiled in Mother’s own sense that God was absent.

What made Mother Teresa unique among God's saints?

The length of her interior darkness; the way she grasped the "'painful thirst' in the Heart of Jesus for the poorest of the poor." Her special way of sharing in Christ’s own thirst on the Cross.

What made Mother comfortable and quiet in hospital?

Her Hindu doctor could not explain it. But when the priests brought the box to the room, Mother, even in her greatest final illnesses would be quiet and calm. The doctor told the priests, bring her the box. What box was he talking about? The tabernacle. 

Did Mother take advice in her later years?

Yes. In 1995, she made a trip to the USA. When she was in Charlotte, she met her old  friend Bishop Curlin. They spoke about her interior emptiness. She liked the advice he gave her.

Did anything change as she got closer to death?

Her letters got shorter. One of Mother’s great tasks as Superior was communication with all the houses and various leaders in the Church. She also had much personal correspondence to keep up with among those who loved her. As she got closer to death, her correspondences were more brief. She loved to tell people to make “something beautiful for God.”