I have friend at 5'9, no one doubts they look perfectly female, and they are, non-GID. They look great and people know this.
The thing is sometimes people aspire for the "classic female model", that's not true, saying the average height is 5'5 doesn't mean that 5'7 isn't feminine. Models requirement is 5'9.
http://img239.imageshack.us/img239/303/15px4.jpgShe is 5'8.5. She is taller than you! she is rated as one of the most beautiful women in the world
I'd happily be 5'7 tall. Don't let the dysphoria take over you on the things which aren't really there.
I'd support FFS and even body contouring but saying you want to get shorter at 5'7 is nonsense you should realize that it's you hurting yourself if you are ever bothered with it.
I had FFS (Chin and Nose surgery) almost two months ago (I put photos in the FFS page), I told my psychologist that in the support group people told me "don't do it! be yourself, it's all attitude bla bla bla, accept things" and that I went and did it because I felt it is important.
Her reaction was "I am glad you did it. It went really well! Now in psychology we actually encourage people to change what they can by surgery if they feel the need for it. Previously people taught to accept things as they are and that there is no need. Now we say that as long as there is truth to it and the reasons are right, you should go for it"
And in your case I'd say go for any body improvement you want but say thank you that you are 5'7, it'\s a great height, I am jealous of your height.