Unless you're pretty slender, it's very difficult to have slim, delicate arms. Lifting weights is actually the best thing you can do to have nice arm definition. Don't be afraid of weight training; it really can make you lean and strong. Women cannot, naturally (without steroids), become bulked up with muscle! We DO NOT have enough testosterone. A combo of cardio and resistance training is the key. Of course, with less body fat some boobage loss is likely. I decided MANY years ago to be happy with smaller breasts and a lean body. If you're thin, your boobs will probably be small; if you have more weight on you, then you'll have bigger boobs. Simple. Just because the standard of female beauty has changed to something akin to huge boobs on a stick (which almost always requires starvation and breast implants), doesn't mean I'm going along with it. Eat healthy, get lots of cardiovascular exercise ... and heave those weights.