Anonymous wrote:20 is really small. It won't last very long in any case.
Anonymous wrote:Go for the 24" bicycle. You can adjust seat height pretty easily. But, be careful about reach (length between the seat and the handle bars). Girls tend to be shorter in the torso and longer in the legs in comparison to boys, so the bicycle may be uncomfortable if your daughter has to lean out too far to get to the handle bars. My daughter (about same size) prefers a cruiser (beach) bike to a mountain bike because she did not like to be so far forward.
Anonymous wrote:I think Isla bikes has a good guide for bike sizes for kids.