More reps will build muscle, not more weight, after a while you can add more weight and more reps.
The lower the weights, the stronger and leaner your muscles will become with more repetitions. If you want bigger muscles, you should try heavier weights.
Even if you use weights to tone your butt you won't make it larger as long as you stick with lighter weights (or no weights) and more repetitions. If you were to use heavy weights and less repetitions, that would build the muscle and therefore make your butt appear bigger. Lighter weights and more reps will just tone and add definition.
Leg presses will accomplish this - but don't overdo. Increase weights very gradually. Advice from a trainer is ideal. For the aerobic component, jogging - or, better yet, rollerblading - is very helpful.
Lift weights with them
Weights, or simply gravity, Blood Fills the veins and they look bigger
Get bigger
It get bigger and lumpy
you get bigger
I am a boy me like this Question when your 8 the breast will start to develop it should end when your 17
Exercises like push ups can develop the pectoral muscles to make them look bigger. If you are young, it can develop when you are mature, and pregnancy certainly will increase its size. Other options are to use padded Bra or opt for Surgical augmentation
You could take steroids but those can kill you.
Alot of squats using free weights.