It depends on the community. Many girls are encouraged to get higher education degrees to support a husband in kollel and eventually a family. But when they put a marriage on hold to further their education, the bochurim settle for a nice young girl. And really, if a woman has that much more earning power, who is going to raise several children, clean the house, and bake the challah? So, they stay unmarried while the poorer kallah starts a family much younger.
