There is no way to shorten the torso, ever. Impossible. You just can't reduce the length of the spine. I mean it. It's just after brain transfer surgery on the "definitely impossible" list. I mean it. No chance in hell.
The only surgery that can shorten you is cutting part of the femurs off. It can maybe take 5-10 centimeters off your height. Though that surgery is expensive, has super long recovery times, doesn't guarantee you'll be able to run or jump again, and makes you look awkward because your proportions are broken.
I see no valid reason for that surgery. If you're REALLY SUPER disturbed by your height, I suggest moving to Norway or another place with tall people. But even if you were 7' high, I'd never recommend the surgery. It's almost like cutting your hands off 'cause they're manly.
PS: 5'6 may be pretty tall for a girl, but it's still below male average (so you're lucky to even be that small, statistically), and not THAT rare to encounter.