Shakespeare had some very strong women. In fact, in a lot of his plays women are held back by society but fight any way. For example, Lady Macbeth makes her own choices and makes choices for her husband. Ophelia practically started a gender revolution, and Juliet defied her father.
I would agree that Lady Macbeth is certainly not relegated to the social sphere. In fact, she is the driving force behind Macbeth's political ambitions.
In Juliet's case, her situation is primarily confined to the social sphere, but then again, she is a teenager. One interesting point about Juliet, though, is that her fate and Romeo's fate does have political ramifications--the Prince actually learns from their suicides and changes one of his laws.
Lady Macbeth is not really relegated to the social sphere, at least not completely. Of course, she isn't the one who is actually getting the political power, but she certainly gets herself involved in her husband's political affairs. She is definitely willing to try to tell him what to do in political terms. So she's not completely shut out of that sphere.