Daughter of Winter

About two thirds of the world experiences some form of winter, either during November through March, or May through August. If a stranger came up to you with the question "What causes winter?" you might say something along the lines of the tilt of the world on its' axis, relative to the sun. You would be wrong.
In fact, all 4 seasons are controlled by 4 powerful spirits. Winter, Spring, Summer, Fall. Those aren't their actual names of course. We'll get into that later, though. Every few millennia, the spirits grow tired, so they take the guise of a human, and mate with a compatible human to produce the new generation of seasons. I am the daughter of one such spirit. I'll let you figure out which one.