As an object falls the friction with the air tends to slow it down. For most objects this does not make a noticeable difference to how fast it falls, particularly if is is only falling over a short distance. If the object has a large area then the air resistance will be greater and it will have more effect on how quickly the object falls. An obvious example of this would be if the bungee jumpers wore parachutes. The parachute increases the area, which increases the air resistance and slows the bungee jumper down.
Small people tend to have a slightly larger area for their size than big people.
So there is a possibility that the effect of the air resistance will be slightly greater on the small person. The small person may therefore fall slightly slower than the big person. The greater the height that they jump from, the more likely it is that there may be a slight difference in how quickly they fall. It is possible to investigate the situation by dropping different objects at the same time and comparing which hits the ground first. Factors such as the weight, the size and the shape of the objects can be investigated as well as the height from which they are dropped.