Act I, Scene VII: Lady Macbeth walks in on Macbeth (while he decides not to go through with the murder) and she accuses him of being a coward. Lady Macbeth urges Macbeth to go through with the murder. Macbeth then cahnges his mind and they go through with the murder.
Act II, Scene I: Lady Macbeth is not present in this scene.
Act II, Scene II: Lady Macbeth meets her husband while he is holding a bloddy dagger. Lady Macbeth goes back to Duncan's bedchamber to replace the dagger and to smear the King's guards (which have been drugged) with blood.
Act II, Scene III: Lady Macbeth is not present in this scene.