It’s the blog post that has got lots of parents talking . Would you be happy if another parent stepped in to discipline your child?

Chicago-based mum of two Karen Alpert took to her blog to applaud a stranger for chastising her own son when he refused to wait his turn at a playground.

The stranger told Alpert’s son to “knock it off” when he pushed in front of another kid to have a go on the monkey bars.

In that situation I would say the majority of parents would bite their tongue and encourage their own child to play on something else. However, this mum did what most of us would want to do – step and reprimand the ill-mannered child.

We’ve all been there. Our children are happily playing, waiting their turn nicely when some rude, ill-disciplined child rocks up and refuses to play by the rules. They disrupt a totally happy, healthy and ordered scene with their horrible little energies.

Karen Alpert and her family

Most of the time they are accompanied by equally ill-mannered mums who either actively encourage their children to behave like this, seeing it as a survival of the fittest style of parenting or are too liberal-minded to acknowledge there is such a thing as the unwritten rules of social order – their offspring Aspen and Allegra being such free-thinking individuals.

If you dare to say anything you are either shouted down by the former or sneered at, pitied even, for being so well, er, narrow-minded by the latter.

More from Tabitha Ronson The little madam engaged in a battle of wills - with me

Children need and respect boundaries. It’s never normally the children but their parents who make a fuss if an adult questions their behaviour.

In her blog, Alpert suggests parents should support one another, have the courage to speak up if a child needs telling off and equally thank the parent who bravely steps in.

I agree. However, if everyone played by the rules, showed respect to those around them, and acted like fair and rational minded citizens then we wouldn’t even need to be having this conversation – and praising a parent for acting like an adult.