Posts are getting shorter because I have too much on my plate these days. Sorry!
The obligation of a husband to support his wife (mezonos) is a quid pro quo exchange for his right to collect whatever her earnings are (ma'aseh yadayim). The Bavli writes in many places that this takanah is for the women's benefit; should she choose to, she can declare that she wishes to keep her earnings and forfeit the husband's support. Just saw an interesting Yerushalmi at the beginning of the 11th perek of Kesubos seems to disagree and hold that she is bound to turn over her earnings to the husband in exchange for his support.