Tanya Plibersek's decision not to contest the Labor leadership should be taken for what it is; a decision by a grown-up person, taken after weighing up relevant factors.

Only she and her family can know — especially after years of work as a minister and then as a senior shadow minister requiring the sort of travel that would make an ordinary human wilt — what is possible, and what is not.

These decisions (Can I go for this promotion? Can I step up my hours at work? Can I take on more responsibilities?) are made every day by women in jobs far less prestigious and well-paid than Ms Plibersek's, as she readily points out whenever she's asked about this stuff.

And no-one could deny that she has been an extraordinary multitasker, bringing her babies to Parliament when they were little, juggling the demands of family like the increasing numbers of women who give birth while serving as MPs do.

Only Tanya Plibersek and her family can know if the time is right to take on more career opportunities. ( ABC News: Nick Haggarty )

Here's the thing, though; these are, as a general rule, the sorts of decisions that plague mothers in politics and yet do not seem to interfere unduly with the decisions of fathers.

Why is it harder for women?

It's worth noting that of Ms Plibersek's leadership contemporaries — the leader and deputy leader of the Liberal Party, and the man who's led Labor for six years — all three have combined their jobs while bringing up young children.

When Scott Morrison and Josh Frydenberg were voted in as the Liberal Party's new leadership team, they became the first PM and Treasurer duo since Malcolm Fraser and John Howard in the mid-1970s to take on those roles while raising primary-school-aged children.

And yet, no-one asked for weeks how they'd manage it all (even though one suspects that had either of them been female, they'd have been interrogated on this point straight-up).

No-one wondered how Scott Morrison or Josh Frydenberg would juggle parenting with demanding careers. ( AAP: Sam Mooy )

Bill Shorten has for six years lived the demanding life of an opposition leader; his youngest is the same age as his deputy's youngest.

Of the other potential Labor leaders in the mounting-yard, two — Chris Bowen and Jim Chalmers — have young families too.

Are wives the secret to political leadership success?

The historical difference? Wives, primarily: men in politics get 'em, and women don't.

Wives are a non-declarable yet potent political asset; organising kids and comforting them when their dads aren't there, standing in at electorate functions, keeping things ticking over, as Margie Abbott and Natalie Joyce and Carolyn Pyne (to name a few, who received varying degrees of reward for their constancy) did for years and years, enabling their husbands successfully to combine work and family.

This is not to suggest that political dads don't suffer the terrible wrench of leaving their children. They do; we just never ask them or worry about it the way we do with mothers.

It's not to suggest, either, that Mr Tanya Plibersek (the accomplished Mr Michael Coutts-Trotter) is not a terrific father.

I'm just observing that even in this modern age, things still work — in general — very differently in Parliament for mothers and fathers.

Margie Abbott kept things ticking over while her husband Tony focused on his political career. ( ABC: John Donegan )

Stanley Bruce, James Scullin and Ben Chifley — who governed in the 1920s, 1930s and 1940s — did not have kids. They are the exception to the prime ministerial line; every other bloke who's done the job has had kids, ranging from Chris Watson's only child to Joseph Lyons' decidedly impressive 12 (even more impressive given that his wife succeeded him in his seat).

And yet of the women who have been prime minister or deputy prime minister or deputy leader to a prime minister, there is a 100 per cent childlessness rate.

If we want women in Parliament we need a solution

Given the national discussion of late about the representation of women in Parliament, what is the solution to this?

Can women win? Julia Gillard became Australia's first female prime minister but she was criticised for not having children. ( ABC News: Tim Stevens )

A national airdrop of generic wives would be helpful, but impersonal.

Plus, it would maintain the fiction that in any modern family it's actually possible, any more, for one parent to take on the full whack of caring responsibilities while the other is absent the entire time.

Here's an idea. Given the general disaffection with the "Canberra bubble", why not pierce it and radically increase the proportion of federal parliamentary business that's done by teleconference?

If MPs spent more time in their electorates, they'd not only be able to go home to their families each night, but they'd also find themselves more influenced by those yelling at them about local issues than those yelling at them about factional or ideological divides in the airless corridors of Parliament.

It's just a thought.