I would think that someone who was sinless would have nigh perfect faith, yet Mary did not calm storms, walk on water, or cast out demons.
Then he got into the boat and his disciples followed him. Without warning, a furious storm came up on the lake, so that the waves swept over the boat. But Jesus was sleeping. The disciples went and woke him, saying, "Lord, save us! We’re going to drown!"
He replied, “You of little faith, why are you afraid?” Then he got up and rebuked the winds and the waves, and it was completely calm.
- Matthew 8:23-26
Then Peter got down out of the boat, walked on the water and came toward Jesus. But when he saw the wind, he was afraid and, beginning to sink, cried out, "Lord, save me!"
Immediately Jesus reached out his hand and caught him. “You of little faith,” he said, “why did you doubt?”
- Matthew 14:29-31
Jesus rebuked the demon, and it came out of the boy, and he was healed from that moment.
Then the disciples came to Jesus in private and asked, "Why couldn’t we drive it out?"
He replied, “Because you have so little faith. I tell you the truth, if you have the faith as small as a mustard seed, you can say to this mountain, ‘Move from here to there’ and it will move. Nothing will be impossible for you.”
- Matthew 17:18-21