Aside from the obvious manifestations of Lady Macbeth's guilty conscience in Act 5, scene 1, quote another piece of evidence,
discussed early in the scene, that reveals Lady Macbeth's mind is never at ease in Macbeth.
In her guilt, Lady Macbeth has become what is know today as Obsessive-Compulsive. That is, she exhibits behaviors that are repetitive, unnecessary, and illogical. Often with OCB (Obssessive Compulsive Behavior) people focus on something that becomes critical to them for various reasons. One such reason can be guilt; this is the case with Lady Macbeth who continuously tries to wash imaginary bloodstains from her hands. In her mind that is tortured with guilt, she perceives King Duncan's blood upon them: With a cloth she wipes and wipes, decrying,
Out, damned spot! Out, I say!....Yet who would have thought the old man to have had so much blood in him? (5.1.35-36)
In addition, she wants light around her all the time, feeling that she is surrounded by darkness. The gentlewoman tells the doctor that she has light by her continually: " 'Tis her command." When the doctor remarks "You see, her eyes are open," the nurse replies, "Ay, but their sense [power of sight] are shut." (5.1.21-22)
Not sure if there is ONE more evidence aside from the sleepwalking, but she does engage in several behaviors during these episodes that definitely show that her mind is never a ease. This is first, as you know, is manifested in her troubles sleeping and in her tendency to sleep walk.
The second is that, during her sleepwalking, she is taking paper, folding it, writing on it reading it, then sealing it, and then going back to bed. This may be her desire to write out her confessions, or to write out her pain.
Another is her tendency to wash her hands several times a day. Her gentlewoman quotes how, during her sleep walking spells, Lady Macbeth rubs her hands together and complaints about blood. She also says that, during the daytime when she is awake, Lady MacBeth also washes her hands by rubbing them together, and that this became a habit of hers, and a clear indication of her guilt as well.
Lady Macbeth had been the brain behind the entire scheme of instigating her husband Macbeth in murdering King Duncan and had actively participated in covering up the crime. Now, in Act V Sc.1 it is obvious that her conscience convicts her and she is overwhelmed by a deep sense of guilt.
In Act V Sc. 1 in the famous 'sleep walking scene' Shakespeare dramatizes objectively her diseased mind through the conversation between the doctor and the 'gentlewoman.'
Other than her pathetic efforts at washing away the non existent blood stains, at the beginning of the scene the 'gentlewoman' tells the doctor,
Since his majesty went into the field, I have seen
her rise from her bed, throw her night-gown upon
her, unlock her closet, take forth paper, fold it,
write upon't, read it, afterwards seal it, and again
return to bed; yet all this while in a most fast sleep.
Lady Macbeth even in her sleep wakes up and writes something on a sheet of paper and then folds it and keeps it safely in her closet. This strange act of hers is clear evidence that she is psychologically disturbed.