Tired mum Kate needs you by her side, William

WITH two children just 22 months apart, it hardly comes as a surprise to find that the Duchess of Cambridge has been scaling back on her social life of late.

Even if you have plenty of help — as Kate does — having two such young children (Princess Charlotte was born in May and Georgie Porgie’s second birthday was i n July) is all-consuming.

It doesn’t matter how many nannies, night nurses and mopper-uppers you employ, it’s exhausting in ways that only other mothers can understand.

The last thing you need — or, quite frankly, are capable of — is to have to make small talk at a wedding.

So, no surprise that Kate failed to show at the South Devon nuptials of socialite Daisy Dickson and estate agent Bear Maclean on Saturday, even if her hosts were informed so late t hat her name was sti l l on t he seating plan.

Or that William has been to at least five weddings on his own in recent years — even knocking out part of a tooth while enjoying one reception.

First, Kate has far better things to do than play trophy guest to assorted pairs of Sloane Rangers, however charming.

Second, it’s not as though she can just chuck on an old Issa frock and pitch up in her nursing bra. She’s the Duchess of Cambridge: if she looks weary or even fractionally dishevelled, the entire world goes bananas.

Far better to give it all a miss and turn in early with the babies.

NO,THE r e al mystery is Wi l liam, who seems doggedly determined to maintain pre-baby levels of partying to the point that, in order not to disappoint the new Mr and Mrs Maclean, he turned up with Pippa, his wife’s sister, in tow.

I know those Middleton sisters are close, but even for such a tight-knit family, that does strike me as slightly odd. A tiny bit creepy, even.

Though clearly it didn’t bother Prince William. Much to everyone’s surprise, they both stayed the night and even pitched up to lunch together the following day.

While there are few men l ucky enough to have a sister-in-law as ac c ommodating a s Pi ppa, t he i ncident does illustrate a universal problem: the challenges that children bring to a marriage.

I remember the stage that Kate and William are at so well. When my children were that small, I was so overwhelmed that I could barely get dressed. And even when I had childcare, my brain felt so befuddled that I struggled to do anything constructive with my free time.

My emotions were in turmoil. I t felt li k e ev e r y o n e — ch i l dr e n , husband, employer — wanted a piece of me, and I was spreading myself thinner and thinner.

On top of that, I felt insecure about my appearance (even though, as my grandmother would have said, no one’s looking at you, dear), while at the same time feeling under immense pressure to seem as though I had everything perfectly under control.

Kate, for all her privilege, slim hips and swishy hair, will be feeling no different. And while she might be fairly relaxed — relieved, even — to have William out of her hair from time to time, it would be very bad indeed if it became a habit.

Women at this stage of motherhood can be fragile.

Prince William is a charming young fellow with lots of friends and, of course, he must enjoy himself.

But he also needs to remember that while Kate’s primary responsibility at the moment are the children, his primary responsibility is his wife.

Making sure she is happy, well and properly supported — not least by his presence — should be his first priority. And if that means a few extra nights in, then so be it.

After all, he’s the future king of Britain and will never be short of a party to go to.

With fatherhood, by contrast, there are no second chances.