As a woman, she would have been socially pressured to appear less ambitious and encouraged to hide her desires
Lady Macbeth only encourages her husband to carry out Duncan's murder and does not herself commit it</b>
Lady Macbeth
She can be viewed as more ruthless and single-minded in her ambition than Macbeth
After Macbeth receives the Witches' original prophecy, he is not satisfied or resolved to act on it and seeks his wife's counsel
Lady Macbeth then "pours her spirit into [his] ear" (A1.S5.L24) and directs his actions, all the while persistently questioning his manhood
Lady Macbeth uses gender norms to shame Macbeth into committing murder

The power dynamic between them is uncommon for the day - a wife would have been expected to be submissive and accepting of her husband's orders
In a reversal of this, Lady Macbeth wields power over Macbeth and directs his actions
Lady Macbeth
Due to her ruthless ambition, she would have been viewed as a masculine character
A Jacobean audience might have been inclined to view her particularly negatively on the assumption that she is untrustworthy because she does not conform to accepted gender norms