Agreed that smaller wheels make sense for a small rider. How small depends on how the design needs add up. One of the pitfalls of this issue is that each builder has solved their challenges with a certain approach. What I've read in the replies makes me think that no one has yet seen the answer. 4'8" is very small. I'm surprised that 700c wheels have been found to work well. The rider needs to explore and ride bikes with 650c and 520ISO wheels for long enough to know what feels best. Andy.