Why did Kate Gosselin Spank Leah?

A group of paparrazzis have shot a picture of Kate Gosselin spanking Leah (one of her daughters). People might have known that the marriage of Kate Gosselin and her hubby Jon are in the rocks so to speak. So how will this affect their marriage? Can this Kate Gosselin spanking Leah picture be used in case they file a divorce? Well, one thing is for sure, we do not know yet the circumstance of this alleged "spanking" incident on Leah. Who knows, Kate Gosselin might have a valid reason for this.