Foiling Around with Lady Macbeth and Banquo

We talked in class about how Lady Macduff acted as a foil for Lady Macbeth and how Lady Macduff had a maternal instinct which contrasted Lady Macbeth's lack of maternal instinct from the spell in the beginning of the play. Another interesting comparison would be Lady Macbeth and Banquo because Banquo is very similar to Lady Macduff in some ways. He has a paternal instinct where he wants to protect his son, Fleance. This is especially apparent when he dies and says "Fly, good Fleance, fly, fly, fly!" as opposed to something along the lines of "please don't kill me".  It's also interesting that Banquo and Lady Macduff are the only two characters to have this direct contact with their child.  With Lady Macduff this is regarded as maternal instinct, so it's as if Banquo is taking the role of mother. Lady Macbeth also switches her role by acting as the "man" of the marriage and questioning Macbeth's manliness.