We do not have Mother Theresa every thought put on paper. I would never assume to know the whole of a person by letters she wrote. So how you could judge Mother Theresa incorrect puzzles me.
I don't know Mother Theresa. All I'm going by is that, based upon information from the person who wished to canonized her, for the last half of her life she repeatedly wrote letters questioning the existence of God. Personally, if someone knew this, why would anyone seek to have her canonized? That is what puzzles me.