Delfina, you may not have to get a whole new saddle. If you like the one that you have got, you might be able to just find some shorter leathers that will fit you, or you might be able to punch enough holes up farther on the stirrup leather to allow you to make it shorter. I had to punch 2 more holes in my old saddle so that the stirrups would fit.
Or anybody that makes or repairs saddles could replace the leathers that will go shorter. If the saddle fits well there is no need to replace it because of the leathers. They usually cost about 60 dollars per set to replace around here.