Well obviously how ever big there butt is.
Big girl with big buttocks.
tone, firm, rounded, but not too big
Evolutionarily speaking, it is to attract potential mates. A large buttocks indicates fertility and that the female will be able to carry and bear young. This is why women developed wider hips and larger buttocks than men.
To get big buttocks you have to eat healthy food and take exercises also have to massage them alternate.
Excercise, my friend. Go and find a good gym or if you've got the money a good personal trainer. That should reduce the size of the buttocks a alot. Also consider if her buttocks is either mainly muscle or fat, because just because she has a big buttocks does not mean that she is fat, as she could have large muscles in the buttocks to comphensate for large breasts or other work.
For some people, the pubic hair can grow into the area between buttocks.
Doing a buttocks injection is simple. You find the spot where the needle of solution needs to go in, insert the needle, and inject the fluid.
Buttocks
So that big buttocks can do the tour de france with homosexua beards
It is not necessarily easier for a woman with large buttocks to give birth. Sometimes the size of the pelvis is not related to the size of the buttocks and it is actually the pelvic area that impedes the birth process.
A female's pelvis is wider than a male's pelvis, especially if a woman has had a child. The male pelvis is narrower and remains narrower throughout life. Also note that some races have smaller buttocks while other races have larger buttocks. The only way to change buttocks that are narrower and flatter to get fuller, bigger, or plumper is if a person becomes obese or if they have filler injected (a surgical invasive procedure).
The buttocks can wiggle and jiggle when a person dances. The buttocks do not dance--they don't have that ability.