‘I have an announcement to make,” says my sister, on FaceTime. Holy cow. Is she pregnant again? She swore two kids was her limit, but I guess she must have had an accident.

“Yeah?” I say, already thrilled about my third niece/nephew.

There’s a pause. She’s really milking this.

“I ate poo,” she finally says.

I blink.

“You what?”

“I ate poo. I ATE POO.”

What follows is a tale as old as time. My sister had made the usual Brooklyn Mom healthy bean mulch for my two-year-old nephew’s dinner. The bean mulch is brown. Poo is brown. She’d just changed my nephew’s nappy and, while back to making bean mulch, spotted some brown on her finger.

“Ah, some delicious bean mulch,” she thought to herself before – without a second thought – licking the brown off her finger. But it was not bean mulch. Not at all.

“What does it … taste like?” I ask, having clawed my way back to composure from a laugh/cry meltdown.

“LIKE POO,” she says.

Eleanor Margolis’s mother, with Eleanor’s one-year-old brother

Then and there, I easily could have made the decision never to have kids of my own. The decree that parenting carries even the smallest risk of accidental poo-eating should have knocked me off the fence like a great, turdular cannonball. But I’m not sure it did. Around the same time as poo-gate, a couple of other things happened.

I’ve always been worried that I look more like my dad than my mum. With all due respect to the latter, he isn’t exactly Audrey Hepburn. He’s – as a lot of dads are, to be fair – a large, hairy oaf with a giant head. I inherited his unmanageable hair and thin upper lip that my mum always insisted was both full of character and quintessentially Jewish. Luckily for my mum’s vagina (there’s something I never thought I’d write …) I did not inherit his enormous head. Meanwhile, from my mum, I inherited ferocious premenstrual syndrome. And that’s about it. Well, that’s what I thought until I found an old photo of her looking so much like me that she could, well, be my mum. Aged 28 – exactly the same age as me, spookily – she’s sitting with my one-year-old brother on her lap. Unceremoniously, I cropped my blob of a brother out of the photo when I posted it on Facebook next to one of me looking identical to her.

Although it was a relief – for once – to look like my beautiful mum, the baby I’d lopped off the photo began to bother me. That’s to say: never had it weighed so heavily on me that, at my age and my face, my mum had two children (my sister had already been on the scene for three years) and the deeds to a house. I, the disappointing 21st-century remake of the classic that was my mum, have clinical anxiety and a cat who gets an erection every time he cuddles up to me.

Without wanting to perpetuate boring stereotypes about millennials: I don’t really know what a pension is and I just spent £7.99 on a Groupon for some solar-powered fairy lights for a patio I don’t own. Unless writing think pieces suddenly becomes extremely lucrative, I’ll never own a house. And, let’s just clarify, no, giving up my “buying pointless crap online” habit won’t mean I suddenly, or even in 20 years from now, have an £80,000 deposit for an abandoned fridge in Penge that a tapeworm of a landlord has converted into a studio flat. But having a kid, well, that’s a slightly different matter. Again, affordability is a huge, glaring issue. Although I don’t have a biological imperative to own a house.

Maybe, in 2018, 28 is way too young to start obsessing over whether I want children. It’s now not unusual for women to have babies in their late 30s and even into their 40s. And any fretting over my “biological clock” runs the risk of turning this into a Cosmopolitan article from the 1990s. But, since my mid-20s, this weird thing has started happening to me where I sometimes see babies and don’t feel physically and emotionally repulsed. I have been known to say, “Aw”.

This may be related to becoming an aunt when, four years ago, my sister had her first child. When I saw my weird, hairless puppy of a niece for the first time, I basically ovulated on the spot. Those bits in films and on TV where people give birth, then have a nervous breakdown over how perfect and beautiful their screeching blob is, started to make a bit of sense.

The thought of bringing a child into a world without my mother's feral sort of love was unbearable

Then, on a cold November afternoon, my mum died. Almost as soon as she was diagnosed with stage-four lung cancer less than a year earlier, I’d lost the will to have children. My mum had coached my sister through two pregnancies, and loved the resulting grandkids with a ferocity that I’ve only ever seen in nature documentaries. The thought of bringing a child into a world without her feral sort of love was unbearable.

Meanwhile, my mum got more and more ill. She lost mobility and stopped laughing. Her shoulders withered and looked like a child’s. She developed a strange, sour smell – the smell of cancer? The smell of death? And, oddly, the closer to death she came, the closer I came to changing my mind about having a kid. Mostly, I’ll admit, as a “fuck you” to whatever higher power (if such a thing exists) that dared to take my mum away from me. You kill one of us? I’ll make more. I wanted to have a thousand babies. I wanted the universe to choke on my family. Maybe there’s some instinctive urge to “repopulate” after a death. I only hoped that my furious hatred of my mum’s illness could be translated into furious love for my own child.

There comes a time in your lesbian life when your brother offers to impregnate your girlfriend. Right …? OK, this may be a Margolis thing, but, either way, I reached that time last year. And it was at my brother’s wedding. As we sat down to dinner, we found wedding favours in the form of literal favours. That is to say, my brother and his now wife wrote each one of their guests a note, offering a personally tailored favour. Babysitting for their friends with kids, that sort of thing. Oh, and a sperm donation for me, the lesbian sister.

Well, specifically, for my girlfriend, if that makes this a tiny bit less Jeremy Kyle. When she read her card, I could tell by her expression – horrified, bemused, amused – that my brother had gone … off piste with this one. But – from a straight brother who does his best – this was clearly a welcome to our strange, uninhibited family.

I don’t know if we’ll ever take him up on his offer. A while ago, I wrote about the London Sperm Bank’s app, which is touted as being like Tinder for jizz. Having become oddly fascinated by swiping my way through different sperm donors – I haven’t deleted the app from my phone. And there it remains, semi-tempting me to shell out £900 – which I can already in no way afford – for a make-your-own-human kit. My brother’s offering, meanwhile, has the advantage of being free and linking me, genetically, to my child. And I could get used to being “Auntie Mum”.

Whatever I choose (or don’t, as is likely for at least a good few years) I have – through the very worst of times and the very best – discovered an unassailable truth about family life: that it’s all, in the beginning and in the end, just jizz, death and shit.