Churchill's daughter, Mary Soames, departed this world last week having led a splendid life.

She was taught that 'we must all rise to the level of events,' and she did.

In her teens, during the war, she joined the auxiliary territorial service. In her 20s she married and focused on her husband and five children. She delayed completion of a biography of her mother, Clementine, because she 'put wifely duties first.'

The book won the Wolfson prize. A new life opened up with four more books and the chairmanship of the National Theatre board in London. In 1980, she was appointed a dame. She died aged 91.

Throughout her life there was a time for everything and everything was in its time. Kirstie Allsopp would approve. Ms Allsopp, the bossy- boots of the property programme Location, Location, Location, is once more taking the nation to task. This time it's about the way young women are structuring their lives: how they're missing out on babies because they're doing things back to front.

They have 15 years between leaving school and a dip in their fertility. They should be breeding, not trying to cram in university and career. Better, she says, to leave school, get a job, buy a flat, find a nice man and have children. They'll be living so long they can catch up with university in their mid-40s.

It's a bit of a gob-stopper, but is there something in what she says?

Well, she's right about the rising numbers of women who don't have babies. The overall birth rate is rising because of immigration, but one out of every five women born in 1967 was childless at the age of 45. That could rise to a quarter of women born in the 1970s. The last time childlessness reached these levels was in the wake of the First World War, during the Depression. So what is causing it this time?

For a start, it's not a want of sexual activity. I find it just as hard to think that educating women to degree level renders them barren. But Allsopp does have a point.

Women enter a competitive career market with men who can afford to give it 10 years of dedication to get established. Many men don't settle down until their mid-30s. The women who keep pace with them then find they've left it too late for babies.

The fertility dip at 35 is a fairly recent realisation. Women used to think fertility carried on to the menopause. I have to add that 35 is an average. I have friends who had children in their mid- 40s. The point is that the risk of being unable to conceive rises sharply.

Women also thought they had a secure fall-back in IVF treatment. Too few realised it has a 75% failure rate.

So yes, there is a sea of heartbreak out there, an ocean of regret. And, in her nanny-knows-best way, Allsopp wants to alert younger women before they too are hurt. She wants them to think through their futures before they find themselves committed to a path that doesn't meet all their needs. I would simply stress that delaying their education needn't be part of that.

Let's take things one step at a time.

To go back to the low fertility rate after the First World War. Obviously a generation of young men had been wiped out. Childlessness was seen as a misfortune because marriage and motherhood was the only life open to women. This, combined with a maternal instinct shared by most, led society to assume every woman wanted children. I thought we had moved on. A measurable minority are childless by choice and I can see why.

My mother, who helped to raise multiple siblings and then five children of her own, dreamed of being a career woman. She spoke wistfully of an independent life engaged in interesting work with friends and concerts and visits to the theatre.

But then Allsopp isn't suggesting a return to the kitchen sink. She isn't suggesting marriage - she is not herself married. She is talking about working straight from school. And since every couple needs two incomes these days, I presume she is also talking about working through parenthood.

Well, I'll grant that university may not be the right choice for all. But it has, or had, advantages. According to the OECD, a graduate in their mid 30s to early 40s will have earned up to twice as much as someone who left at the end of secondary school. Those figures are retrospective. Some experts query whether a degree will be quite so profitable in future (think graduates in Starbucks).

It's understandable that training on the job will mean more to an employer than a soft degree. Four years at university is a big financial drain even without fees. Whether it is always the cost effective option is a decision for both genders.

However, it is university that has made the essential difference to the place of women in society. It is the gateway to the professions. Without a university education, we wouldn't have women doctors, lawyers and economists. Without it we wouldn't be seeing FTSE 100 directorships creep toward 20% or board appointments up by 34% since 2012.

Skipping higher education is no guarantee of anything. Allsopp went straight into work yet she didn't meet her partner until her 30s. He already had children. Fortunately he was willing to have more and so she 'squeaked home' with her two boys. Other women in similar situations find their partner has done with parenthood. And then there are the men who don't want kids 'just yet'. They postpone parenthood.

Society is more complex than it was100 years ago. What encourages me - and my evidence is anecdotal - is that young women who want children say so. When they are one year into a relationship, they'll tell their partner, 'I need to know if you are serious because my time is limited.'

For me the key word in this debate is choice. We need mechanisms in place that make it easy for women who want babies to have them. And we need to celebrate women who choose to have none. In our overcrowded world, this too is progress.

There's lots to like about the life Mary Soames led and (I suspect) the one Kirsty Allsopp would think ideal. But we live in an age that permits it only to the rich.

I applaud the notion of giving a family its due and then starting a career in middle age. But I don't expect those careers to reach the top ranks. I don't see those women in board rooms, being captains of industry or filling the ranks of professorships - currently 86% male.

Meanwhile, with our long hours culture, why would couples commit to a baby when they work the clock round and have no spare cash for child-care?

For my money the solution lies at the top. From there, women who struggled to cope with a family will know what to improve for those coming after them. If their career cost them the possibility of children, they will understand how to redress the balance for others. My hope is that they will bring in child-friendly working without throwing away a century of progress.

Discouraging girls from going to university would be throwing the baby out with the bathwater.