Can a 14 Year Old Girl Have a Liposuction, & the Fat Transferred to Her Butt?

At this age cosmetic surgery of this kind is not recommended    I don't think any board certified plastic surgeon would do this surgery 

Although it is possible with parental permission to have this surgery, I doubt that most ethical board certified plastic surgeons would do this surgery without compelling reasons such as correction of a deformity. 

I would be wary of a surgeon who feel otherwise.