I've seen medical studies that show that the body, when it is gaining or losing weight, is not really "redistributing" fat cells, which would imply that gaining weight increases the number of fat cells and losing weight decreases them. That's not how it works. The number of fat cells in the body always remains constant. (Unless you're gaining a very significant amount of weight, in which case it increases.) When you gain/lose weight, all that happens is that the body's existing fat cells are inflating and deflating with stored fat.
So basically, even with hormones, the body can't magically "store" fat in different places. Your bloodstream carries generally equal amounts of energy throughout the body, and cells regardless of location take that energy and either store it or release their own stored energy to fuel the body's non-fat cells if there's not enough.
So hormones can't influence where the body stores fat while gaining/losing weight. You'll still store any fat from weight gain in the same places where fat cells already exist.
However, with that said, hormones DO influence where new fat cells are created in the body as new fat cells are created. With estrogen in your system and low levels of testosterone, new fat cells will tend to be created in the boobs and hips/butt/thigh area, which means that slowly over time proportionally more fat will be stored there. "Redistribution" happens because the body's fat cells are constantly dying and being replenished, at a rate of about 10% per year (depending on age.) So that's basically what's happening, is that the body's fat cells in masculine areas slowly die off year after year, and then under the influence of estrogen they are reborn in new feminine areas.
Age and genetics obviously play a factor. Some people are biologically programmed to grow fat in different areas, and also younger bodies renew and regenerate themselves faster than older bodies.
