In spite of her extreme strictness and intolerance in most other matters, one thing that mum never smacked us for was bedwetting, or indeed toilet accidents in the daytime – provided they were genuine accidents and not caused by laziness or carelessness on our part. Reading between the lines, I suspect that she herself was a bedwetting child, and so had uncharacteristic empathy for any such incidents.
In fact, I only actually wet the bed two or three times as a young child and while I remember having a few daytime accidents, only one of those earned me a sore bum.