The nest is empty. My parents died, and aged aunts and uncles are falling like flies. Even the family pets have pegged it. All of a sudden the family has shrunk and there is no longer a trail of rancid cereal bowls and mascara-stained towels on the floor. The freezer door is always closed properly and no one leaves the immersion heater on.

Life with just the two of us has become easy to the point of slovenly. We have parallel sofas in front of the TV and blob out; we get up later; we don’t have anyone to set an example to and, if we want to, we can shag on the landing. As if.

Perhaps I should get a gerbil, or a gorgeous cocker spaniel puppy. I won’t put it in a pram or anything, but, subconsciously, I’ll want to. I’ve become one of those old ladies on the bus who tell young mums to “Enjoy it while you can, before you know it they will be grown up and gone.”

I distinctly remember older women doing that to me and feeling like I might smack them to remind them how knackering being a mother of two small children actually is as clearly they had forgotten. They had, and I have, but it doesn’t make the gap left behind any easier.

Everything’s changing. The girls have left home. I mean properly left home as in don’t come home at the end of term to tip out their washing or demand new shoes.

On top of that, we’ve downsized, and down-migrated south to be nearer them. Having lived so far north we might as well have been in the Arctic Circle, it’s been a shock to the system, particularly in terms of the cost of everything. In Northumberland houses are so much cheaper they are effectively buy one get one free, and it was easier to live well.

Here, in Oxfordshire – OMG, it feels like it’s Middle Class Mission Control. I go into charity shops and it’s so upmarket I have to ask whether it is a charity shop or not. There is an entire Farrow and Ball shop since this is the middle-class label of choice.

All this adds up to a lot of changes, huge seismic ones. Life as a late middle-ager is anything but static. All the familiar daily routines have gone – the school run, teatime in front of Neighbours, parents’ evenings, bedtime stories – and they’ve left in their wake a lot of daily decisions.

“Public policy surely needs to wake up to the new generation of older women who are neither in their youthful childrearing years, nor frail and elderly, but need more support than they are currently getting.”

I need to make it all up again as I go along; it feels like there’s no template. Not even the equivalent of a National Childbirth Trust to join to compare notes with fellow travellers. I might start one of those: people round here would be mad enough and wealthy enough to pay through the nose for a course of classes in midlife crisis. Everything has to be reconsidered and reordered and rebooted.

With so many of us heading for old age and living longer, the nature of families in general is changing too. There will be more generations alive at once and fewer siblings, so most families will be more of a beanpole shape. There will be a burden of care at both ends – the kids won’t leave home till later, and the elder generations won’t kick the bucket for ages.

Inevitably the late middle-agers and, in particular, women, are going to cop for most of this. Both our parents and our children are likely to be dependent on us for longer than ever before. Factor in the astronomical cost of childcare and you get some very busy women in their 50s and 60s and beyond. Perhaps this explains why the number of women being treated for alcoholism over 60 has risen by 65 per cent in the last five years. Older women are hitting the bottle.

These demographic changes are already happening. There seem to be almost as many grandparents pushing buggies these days as young mums and dads. In fact, grandparents in middle to late middle age now provide care to an astonishing 40 per cent of families… but interestingly have no rights to take leave to look after grandchildren, and no rights to request flexible work.

Public policy surely needs to wake up to the new generation of older women who are neither in their youthful childrearing years, nor frail and elderly, but need more support than they are currently getting – particularly as most of them now need to still earn a living well into their 60s.

The cushion of the family is also already falling away for many old people, and is exacerbated by the divorce rate. One in three of all marriages are now remarriages. And stepfamilies are the fastest growing family form in Britain, accounting for one in 10 of all families.

Evidently still being married to the father of your children after 27 years like I am makes me something of a novelty. The trend for living alone rather than sticking it out with a long-term relationship is set to continue since the number of single-parent families is also growing, and is expected to rise by 31 per cent from 2013 to 2033 to just over 412,000. Old age then looks set to involve more and more one person households.

It’s another example of the Baby Boomers – and I include myself in that category – having brought about social changes that will have a negative knock-on effect on older age. But then the Baby Boomers don’t do old. They are refusing to get old. For now at least. But when it does catch up with them they are going to have a terrible shock.

It’ll take more than afternoons in front of Poirot repeats to keep us happy.

Images by Hannah Carmichael.