One night about six months ago, as I was tidying up for the babysitter at the same time as battling to put the kids to bed, all while trying to answer a multitude of suddenly-urgent questions they’d had all day to ask, and put lipstick on, I caught sight of my frantic-looking face in the mirror. What, I wondered, was I doing all this for? Was it worth it simply to spend the evening with a couple we didn’t really like, drink insipid wine and make shallow small-talk about other people we don’t really know or want to spend time with?

I’ve always been a more-the-merrier type person and someone who prided herself on being a good friend. I have friends from all areas of my life – school, university, work – but as I got older and the demands of raising three young children and work have grown, I’ve realised that something had to give. And that something has ended up being my friendships. Not all of them, but I’ve certainly had something of a reassessment.

It wasn’t a contrived thing at first. It was more of an inevitable decline as the children have got older (they are 11, almost 8 and 6) which has left me, their designated driver/slave (football one night, Scouts the next, never-ending homework etc) feeling frazzled. But it’s also because, since turning 40 two years ago, I have, I suppose, become less of a social butterfly and make less of an effort generally. I’ve reached a stage where I choose a bath and a book over a night out.

So I decided to prioritise a small number of people, rather than try to keep up and maintain lots of different, superfluous friendships. It started with something of an online “cull”. The “friend” who always tried to make her life look like something out of a Boden catalogue with never-ending perfect images of her children along with the nauseating hashtag #blessed. The mum from school who hardly said a word to me at the school gates but looked at every story the second I posted it on Instagram and probably gossiped about it afterwards. The people who popped up on Facebook who I hadn’t seen for years and these days wouldn’t cross the road to say hello to.

Unfollowing, unfriending and, in some cases, even blocking, made me feel calmer and more in control. It helped prevent FOPO – Fear of People’s Opinion – and quelled the anxiety I sometimes get after sharing something spontaneously on social media. So I began to do the same sort of thing IRL too.

I stopped making the effort with the people who leave it to me to initiate every meet-up and nurture friendships that, in the words of Marie Kondo, no longer spark joy. Those who I had to bite my tongue with, who looked at their phone constantly while I was talking to them. Those who cancelled meet-ups one too many times or who I saw out of a sense of obligation and duty rather than want. The friend who said “Have you really?” in an incredulous way after I told her I’d lost weight.

I stopped texting people back if I didn’t really want to see them, and arranging coffees and lunches unless someone really made the effort. I stopped hanging around the school gates to chat unless someone really made a beeline for me.

I used to view my birthday as a great excuse to get my friends together but I’ve more or less canned that too. Last year I met my husband for lunch instead and I’ll be doing the same again this year.

It’s not something that’s been entirely painless or come without guilt though. I sometimes see people’s names pop up on social media or hear about them in passing conversation and feel a sense of sadness and loss. There are also a few friendships I have lost along the way that I mourn for. Those who fell by the wayside or those I hoped would last. And those where they have perhaps decided I wasn’t worth the effort either.

An autism diagnosis for one of our children a few years ago was also something of a catalyst. The lead up to it, endless difficult phone calls, school meetings, referrals, sleepless nights and then a new school, was really stressful. It highlighted the friends who really cared and wanted to understand what we were going through, and those who didn’t seem to. Maybe they were swept up in their own problems at the time or they didn’t know what to say, but it certainly helped give me clarity on the people I wanted to keep in my life.

I have also taken a more “holistic” approach to friendship. Working from home can be quite solitary and my life is pretty much ruled by deadlines. As time has become more limited, I’ve become more careful about who I spend it with. I see going for lunch with a good friend as being as important as going for a run or to the gym in terms of maintaining wellbeing – but it has to be a frien dship really worth investing in.

I have, as a result, concentrated on nurturing a small number. Primarily, four women I was at primary school with and have known for over three decades. We don’t get to see each other that often because we live in different parts of the country, all work and have 12 children between us, but it’s always lovely when we do.

Our shared history – the fact that I remember their parents’ landline numbers, names of their childhood pets and the boy they lost their virginity to – gives us a firm foundation and a comfortable camaraderie. Theirs is the one WhatsApp group I always want to be in – we share everything going on in our day-to-day lives, from parenting problems to silly gifs.

I’ve also kept in touch with those low-maintenance friends who I don’t see all the time but who always give me a bit of a lift. The neighbour who also works from home who I can meet for lunch at the drop of a hat; my nearby freelancer friend who I can share my work woes with over coffee; the London friend with no kids who always knows the best places to go, makes me laugh and who is always up for an impromptu drink or five. I’ve also made new friends along the way, mainly through social media and with women who are self-employed parents like me.

Overall though, I’ve found that, when it comes to friendships, less really is more –something that has even been scientifically proven. A recent report, from the University of Leeds, found that those with a small number of close friends had higher levels of wellbeing and were happier with their social lives. While they didn’t specify a prerequisite number of friends, I would guess that, for most people, it would be less than you can count on two hands.

The study of 1,496 adults, published in Psychology and Aging, found that younger people had larger social networks but these consisted mostly of “peripheral” friends, such as colleagues or online-only friends. Older people with closer, more positive friendships fared better emotionally. Dr Wändi Bruine de Bruin, the report’s author, said: “If you feel lonely, it may be more helpful to make a positive connection with a friend than to try and seek out new people.” In other words, you need to nurture your existing friendships rather than seek out new ones.

I haven’t had much of a backlash from my friendship cull so far, apart from one angry, highly strung former school friend who sent a flurry of unpleasant messages after I unfriended her. Others have quietly ebbed away into the ether. Which just goes to show, they probably weren’t the best of friends to begin with.

I’ve found focusing on quality rather than quantity much more enriching and it has simplified my life in many ways. I’m spending less money on babysitters too.

Five ways to streamline your friendship group

1. Think about the people you see regularly and text without thinking. Those are probably your core friends.

2. Ask yourself what you get from this friendship and whether you put in equal effort. If the answer is not much and/or no then it might be one to let go of.

3. If you’re not brave enough to delete someone on social media just engage with them less, mute or unfollow them first and see how you feel. If it makes you feel better then that’s a good indicator.

4. Treat others as you would like to be treated. Decreasing contact is kinder than ghosting.

5. We probably all have a number of people who Bridget Jones called “jellyfishes”. Those who seemingly accidentally say something hurtful or leave you feeling low. Ask yourself whether you want those sorts of people in your life.