I am 5' 8", but fortunately for me I have long legs and big feet (Cakegirl are you reading this
) being of a smaller stature may be a handicap at first when you do BJJ, but after you get technique it won't matter much.
For example there were two blue belts at my old BJJ school who were about 5'6" 140. These were SMALL GUYS. Yet, they were fast as hell and could wiggle/slip out of anything. Smaller, faster people are much harder to grab and control when they have the proper technique.