I'm 5'3" at 120 and ride a 15" comfortably. 16" is too big, so I would think a 15 or 15 1/2 inch would be best for you. Also, there are many different seats and styles of western saddles. Personally, I love reining saddles - my seat is much more secure in this one, and seems to have an overall tighter feel to it. The pleasure saddles seem to be flatter built, and then barrel saddles are completely different from those.