In Lady Macbeth's first speech, how does Shakespeare present ambition? How does he present ambition in the play as a whole?

In this speech, Lady Macbeth is reading a letter from her husband in which he tells her what has happened with the witches. The audience already know all that has happened, so rather than focussing on the action, we are instead observing on her response. After she has finished reading the letter, Lady Macbeth starts talking immediately in the future tense, about what 'will be', saying that Macbeth 'shalt be/ What is promised', and that fate is 'to have thee crown'd'. This continues the future tense that Macbeth used in his letter. As this is at the beginning of the play, the audience are also focussed on what is to come. Lady Macbeth's ambition is also emphasised through her own comparison to Macbeth's lack of ambition. She says that he is 'too full of the milk of kindness', and that he would be too inclined to be good. As a solution to this, she promises to help him, by 'pour[ing] my spirits into thine ear', and use her own ambition to help him.