I think that making parenting a D/s thing suffers from moderate flaw: it assumes that a D/s relationship is always benevolent guidance. Sometimes a D/s dynamic in a relationship really doesn't change the person on the submissive side of the equation, and/or the roots of the behaviour are recreational cruelty, because the Dom and sub have agreed that while they are both good people, sometimes the petty and the humiliating are fun.

What I do to my boyfriend when it's my turn to Domme is -nothing- what I'd do while babysitting. No safe words, for one thing, and I don't believe in hitting children. You may, if dealing with a cranky child, restrain them via the firm hug check method and hold them down to put them into snowsuits, or condemn them to corners or rooms, but the other inherent difference between sexual domination and child care (asides from the obvious fact that only the former is a turn on) is that a D/s relationship is supposed to be taking place between two consenting adults, at least one of whom likes to submit, where as children are only submissive to the whims of the parent out of necessity, and only the parent has real right of consent.