I'm glad someone had the nerve to ask that here. I've always wondered how on earth an adult male could possibly have sexual intercourse with a small child.
Only two possibilities in my mind:
The poor girl gets ripped apart; which should be prosecuted as attempted murder, not merely rape.
Or, it shows the perp has “arrested development” in some of his parts.
I once had to do some research on this disgusting topic.
I won't go into the revolting details, but yes it is possible, although how possible varies by child.
In some parts of Asia, notably India and Thailand, there are a good many working prostitutes at this age. And they're generally smaller than American girls.