Breast enlargement surgery
At least from what little research I have done.
Among other things. Insofar as cosmetic surgery goes, what I've picked up with
very minimal searching is that, breast
reduction surgery (for males, in particular), and both ear and nose surgery, at the
least. I can only imagine there's other shenanigans involved in regards to that kind of thing.
It's just... one of those things. I'm not sure about other countries, but in the states kids (especially younger ones) really have very,
very little in the way of legal rights. They've got some protections (against abuse and neglect, mostly, for all the damned good that does some days), but not too much in the way of stuff regarding consent and whatnot. If their parents want them to have a nose job, they're probably going to end up with a nose job. They're not really considered human enough to disagree, yet.
Really, Bauglir pretty much hit the nail on the head regarding this thing. A someone made a rather stupid contract and now they're stuck with it.
I'm pretty sure children need to consent to cosmetic surgery (although this might not include reconstructive surgery). You don't have an unlimited right to do whatever you want to your children.
Some quick searching seems to say they get to consent if they're considered legally competent... which has a general rule of thumb point of being around age 14. Not 3. Otherwise it's just convincing a doctor it's in the kid's best interest. And if you've got the money to have a voluntary procedure done, you've probably got the money to hire a lawyer able to make sure they're convinced.