"Come, thick night, / And pall thee in the dunnest smoke of hell, / That my keen knife sees not the wound it makes, / Nor heaven peep through the blanket of the dark,"(1.5).
She asks directly for "thick night" and "the dunnest smoke of hell", meaning she is calling upon forces of darkness to help her be wicked, whereas Macbeth is more concerned with avoiding "light" to preserve his 'pure' soul.
However, Lady Macbeth does reveal she is concerned about discovery, wanting to stop "heaven peep[ing] through the blanket of the dark".