IT'S the mother of all questions to ask, and today I want to discuss when it's appropriate to ask a woman why she hasn't had children. The quick answer is, never!

It's about as appropriate as asking someone when they last had sex - both are deeply personal questions that will only come with an awkward response.

I have quite a few girlfriends who are childfree and they seem to be very happy in their life. So why is it that society still expects a woman to be happy only when she has children?

I know my friends get asked constantly why they don't have children, and every time it happens, I feel myself getting really angered for them. Are women only validated by the amount of children we breed?

The role of women in society has evolved somewhat since the frilly-apron, muffin-baking Stepford type housewives of the 50s.

Women continue to prove that they are equal to our male counterparts in most industries.

The problem I see is that people have a hard time understanding when a woman advances ahead in a career, that there are always sacrifices, more so than men.

I notice that a lot of the negative criticism stems from our own womankind. Why do we feel the need to judge other women?

Is it jealousy - I know when my kids are screaming their lungs out and I have a pile of work to get through, I have a moments thought for my child-free friends.

When I'm running behind on deadline with book edits, I have been known to threaten my lovely childfree book editor in Sydney with sending her a recording of the screaming in the house.

Even as I write this, I can hear my husband say my toddler's name for at least the tenth time in the space of half an hour.

But then my said toddler will come and tell me, for no apparent reason, that she loves me and I know I wouldn't change my situation for all the tea in China. But that's my life.

So spare a thought next time you wonder why a person has or hasn't had children. Ask yourself, does it really matter to know? If you think it's none of your business, you're bang on!

And to any child-free people out there who feel guilty, I have that recording spare to ease your thoughts!