Jesus was teaching his disciples about the signs of the end of the age and his second coming. In this passage we find him telling the disciples, in the light of the events to come, how they should conduct themselves. The Greek word is agrupneo, which means to be sleepless, or gregoreo which means to keep awake, from which we have the name Gregory. No, that would be impossible.
Human beings have to sleep.
Some people have done that, thinking that is what it means to watch and be awake, but that is not what Jesus meant. No, Jesus was saying that, in view of his coming again, those who are his disciples are to live their lives on a daily basis in view of the kingdom of God, the coming of Christ, and our union with him. To be watchful, then, means we should not be embroiled in the affairs of this world in terms of worldliness. She was a worldly person who forgot all about the kingdom of God. Her perspective was governed by this world.