I’ve decided motherhood is not for me. But being an auntie? It’s what I was born to do | Australian lifestyle

“She doesn’t have kids!” My littlest niece, Bonnie, said to my sister one day, about me.

“That’s why she has so much time to love you,” my sister said. Bonnie did some deep, earnest thinking, as toddlers do when they’re really considering something. Then she nodded, as if to say: yes, that is an extremely valid choice. If only everyone understood so easily.

In many ways, I’m not a suitable candidate for motherhood. I require, for example, upwards of 10 hours quiet, alone time a day in order to function. I have seen my friends and my sister become mothers, I have imagined it in great, excruciating detail for myself and decided it’s not for me.

Apart from anything logical, I have just never felt the urge to make a person with my body. And I do not think it’s compulsory simply because I have the organs to do it.

Being an auntie, though? It’s what I was born to do.

I would give my nieces anything: my favourite necklace, my last hot chip, my life. I love my nieces with a feral sort of devotion that borders on obsession.

There are currently 17,088 photos or videos of them on my phone, and counting. Most days I wear T-shirts I had printed with their artwork, or bracelets they made to spell out AUNTIE KATIE. I have tried to keep every pebble, drawing or glitter unicorn sticker they have ever given me. My cupboards are filled with Tiny Teddy biscuits, my wardrobe with emergency outfits in the right, tiny sizes.

I understand more than ever how close fear is to love; I worry about them all the time. I would cross the seas, go to battle or fight a lion to protect them. In future I may have to be physically restrained to stop me from meddling, if anyone does them wrong.

The idea of them suffering even a minor inconvenience, let alone real pain, causes me distress. Sometimes I wonder if we should, in fact, wrap our children in cotton wool?

The role of auntie or uncle – or, as non-binary Australian musician G Flip suggests, gender-neutral options like “Uncy” or “Auncle” – is often overlooked and undervalued but we can be important figures in children’s lives, if we want to be. And I really want to be.

I’m a bonus safe grownup, a backup caregiver. A keeper of secrets, a teller of stories, a giver of snacks. A keen and willing member of this village we hear so much about needing to raise a child.

Also, kids ask too many questions for their parents to answer them all. How do the colours get into a rainbow? Is God a cloud? What’s a graveyard? Sometimes, it’s me or their uncle who has to explain – and afterwards, we talk about how we may have just contributed to their version of reality.

I know, too, that just by existing in the ways I’ve chosen, I’m showing them different possible futures for themselves. I’ve been in a loving relationship for a decade but we have no plans to marry, so I’ve introduced the idea that marriage is not compulsory. They ask about my vegetarianism and already my six-year-old niece, Poppy, has decided not to eat fish “because it’s mean to the fish”. They understand I write for a living (they’ve put in a request for kids’ books instead of my “boring ones for grownups that have no pictures”) and they’ve started writing little stories of their own. In my own way, I try to gently teach them things that matter to me: we read books about gay penguins in love, make art without worrying about being perfect, and eat whatever we want.

It is a joy and an honour to know that I am important to them. They won’t understand for many years just how important they are to me.

To them, I am someone who is always around and let them have the icing off their cupcake. They don’t yet know how lucky they are to have two loving, thoughtful parents and so many other family members bustling about, waiting to dote on them.

One day, I’ll explain. That their very existence changed me. It made me Auntie Katie and there’s nobody I’d rather be than her.