What to do when ‘mean girls’ grow up to be mean school run mums: I used to suck up to the head of the group, but was secretly shocked by her cattiness. Then she turned against ME with a WhatsApp that left me shaking. This is exactly how I beat them

One playground memory will forever haunt me. On a bright summer’s day, a so-called friend, Lucy, marched over to me, yelling and pointing her finger in my face.

The source of her rage? I’d declined her invitation to a birthday party.

As her voice raised ever higher, and everyone turned to stare, I choked back tears. Thankfully, one of the onlookers was the headmistress, who led me away to the safety of her office.

It was classic example of playground bullying. Except for the fact I was 47 – and my bully was another mum.

This led to me cutting Lucy off altogether, along with the other school gate mums whose friendships I once treasured. And the truth is, I’m happier for it.

It’s left me believing that, despite popular belief that mums can support one another, in fact the opposite is often true.

When I had my children, now aged eight and 13, I wanted women around me who were at the same stage of motherhood. Women with whom I could swap tales of sleep deprivation, fussy eating and more.

When my eldest started at our village primary school in Hampshire, we hadn’t lived in the area long, so it felt doubly important to get to know other mums.

My first circle of mum friends rubbed along without any major dramas, although as my son got older and none of us needed each other like in those early days, the friendships drifted.

However, I’d been left with a favourable impression of being in a mum ‘tribe’. So when my daughter Millie started at the same primary school, I set out to establish the same with the mums of her new classmates.

I was in for one hell of a shock.

The self-appointed head of our group was Sarah, also chair of the PTA. She had an inflated opinion of herself – and a shameless desire to belittle others.

She would ‘recruit’ mums to her circle and, initially, it was nice to be asked to join her posse.

In the corner of the playground was a circular table with a bench around it. Sarah would sit on top of the table while we waited for the kids, ensuring she was looking down on the rest of us on the benches. As other mums arrived, she’d sneer at their clothes… then turn on the pleasantries such as, ‘Oh, hi! You look lovely!’ as they got within earshot.

Though other mothers joined in, I never did. And yet, I worried that if I ever commented on her behaviour I risked breaking up my daughter’s friendships too.

But even as a (reluctant) part of that circle, I wasn’t immune to their cattiness.

When our children were in Year Three, Sarah set up a WhatsApp group when we were organising the summer fete and, forgetting I was a member, sent a message reading: ‘Clare’s bloody useless, don’t bother asking her to help, she makes a mess of everything!’

It wasn’t true; ironically, I’m a professional event organiser. But what really hurt was the personal and vicious nature of the attack, and I found myself physically shaking.

To make matters worse, some others chimed in to agree. I eventually sent a message reminding them, ‘Ladies, I’m on this group’. Tumbleweed.

At one of the children’s birthday parties a few days later, they behaved as though nothing had happened. If I was a confrontational type, I might have had a showdown with Sarah. Instead, I sucked it up.

Which brings me back to Lucy, the mum who gave me a verbal pummelling in the playground that day. She was extremely self-assured and considered herself high up in the mums’ pecking order.

Our daughters, then aged seven, didn’t get on – and yet when Lucy sent round the invite for her daughter’s eighth birthday via WhatsApp, Millie still got one.

She didn’t want to go, and I was increasingly wary of Lucy, so I politely turned it down without providing an explanation – prompting Lucy’s outburst the next morning.

She wanted to put me in my place, shouting and swearing: ‘I don’t want your child at our party anyhow, she’s not welcome!’

After the headmistress had gently led me away, she told me: ‘What I just saw was unacceptable.’

This was the first time anyone had acknowledged that the behaviour amidst the mums was wrong. Until then, everyone had treated the bullying as an open secret we were too scared to discuss for fear of repercussions.

I knew it was time to remove myself from the situation. After the fete, I left the WhatsApp group, and I started standing back at the school gates.

Today, I have just one mum friend at school, but she’s reliable and kind, having also been affected by the mean mothers.

I know the other mums still whisper about me, and no doubt think I’m stand-offish, but I couldn’t care less. I don’t want these women anywhere near me.

My daughter still has friends at school, and that’s all that matters. Because while mum friends can – in theory – be a nice perk of the school years, my experience taught me they shouldn’t be seen as a necessity.

While you choose your friends in all other areas of life, you can’t choose who will join you at the school gates – so there’s no guarantee of you’ll get on. And you’re better off being friendless than enduring the company of the mummy mean girls.

• Clare Senne is a pseudonym. Names and identifying details have been changed.
• As told to Sadie Nicholas