I'm posting sentence 3 again for you to check. I'm includinga few other sentences.
1) Macbeth starts to be haunted by Banquo’s ghost. At the feast he becomes pale because he sees Banquo’s ghost sitting at his place.
2) The fifth act opens with the sight of Lady Macbeth's madness. She walks in her sleep, trying to wash Duncan's blood from her hands. She is so obsessed by her feeling of guilt that she can't wash her hands clean.
3) The doctor thinks that she is sleepwalking because she is mentally ill.
4) Meanwhile Malcolm, Duncan’s son, is marching into Scotland with an army. His soldiers cut branches from the trees of / in Birnam Wood, to use these as camouflage to cover their advance.
5)A servant gives Macbeth the news of the Queen's death. Macbeth says that he can’t think about her now. M still has still one hope: that he can’t be killed by any man born of woman.
1. comma needed in 2nd sentence
2. OK
3. OK
4. use "in" not "of"; otherwise, OK
5. Who is "M"? Otherwise OK.