Looking at the video again, she may be hitting him, but she is not really using full force below the belt. Given any man, when hit at the groin, he will fall to the floor in sharp pain for at least a minute or so.
She is merely teaching him a lesson not to be so naughty with the little one.
Unfortunately, she is being taped. I think she will burst out laughing when she sees what was being captured. As a lady often puts it, served him right to be seen around the world.
This is capital punishment in the making.