One of the best .... and worst parts of working out witih weights is that one's body changes shape. I'm developing a rounder butt than I've had in years .... and years..... whcih is great! My abs are tightening but I still have the fat over top and now it looks worse than before I starting losing the fat. I look like I have a pooch of sorts. that's bad. very bad. of course it probably looks worse to me than it does to anyone else. but still.
"they" (whoever "they" are) say you can't change the shape of your body. I beg to differ. Because I'm doing it. Wiill cardio alone do it? No. You'll end up a smaller version of your larger body. Weight training ... pushing yoru body to use heavier weights than you have before ... is what will make significant changes in your body. Is your bone structure going to change? No. But can you develop a smaller waist, a rounder butt, a more hourglass shape.
Oddly, you can even grow, just a wee bit. Because when you're strong and fit, you stand taller, straighter, and that's how you can grow, just a wee bit taller.
I encourage women to push their bodies. Don't be afraid of using heavier weights (as long as it's safe and you can handle it) ... don't play it too safe. You won't bulk up ... you don't have sufficient testosterone. What you will accomplish, is strength, sexy toned, tightened muscles, great flexibility, endurance, the ability to go from morning to night and still have energy at the end of the day.
A combination of strength training, cardio work, yoga or pilates (for flexilibility ... very important), healthy eating of lots of fruits and veggies, whole grains and protein, lots of water, will give you amazing results!