First, let’s look at what the Renaissance stereotype of femininity was. Women were definitely second-class citizens. Even though Queen Elizabeth was a strong ruler, women in general were expected to defer to men. Men ruled the households. Women were to look as beautiful as possible and submit fully to their husbands. A Renaissance-era woman was expected to care for the house and see that her husband’s needs were met. She was to be patient, kind, gentle, modest, humble, and pious.
Lady Macbeth pretended to be this kind of woman, but as she said to Macbeth, “Look like th' innocent flower,/But be the serpent under ’t.” She was definitely the serpent pretending to be innocent! She welcomed Duncan graciously and prepared a feast in his honor.
The first stereotype which Lady Macbeth breaks involves her relationship with her husband. He addressed her as ‘my partner in greatness,’ which was surprising for that time. But it is clear from the first moment we meet her that she is in control of Macbeth, not the other way around. She devises the plan to kill Duncan and she goads Macbeth into it by attacking his manhood and courage: “When you durst do it, then you were a man.”
She also negates her own femininity in her famous soliloquy:
“Come, you spirits
That tend on mortal thoughts, unsex me here,
And fill me from the crown to the toe top-full
Of direst cruelty!... Come to my woman's breasts,
And take my milk for gall, you murdering ministers…”
Interestingly, however, Lady Macbeth loses her power over her husband once he becomes more evil and ambitious than she does; once he murders Banquo without her knowledge or consent, her hold over him is broken and they begin to grow apart.