Every mother of twins will nod their head at Bec Judd's "twin birthday rules".

Mothers of twins will appreciate that while it might be cute to dress them in the occasional matching onesie or enrol them in the same sports team, the double-up schtick just doesn’t cut it on birthdays. They’re separate little people after all, with separate identities who need separate servings of fairy bread.

That’s why mum of identical twins (plus two other children aged three and six) Bec Judd creates family “rules” to ensure her boys, Tom and Darcy, don’t get half the celebration.

In an Instagram post marking their first birthday on Friday, the 34-year-old model/television presenter/speech pathologist shared precisely what that entails: “Twin birthday rules,” she wrote, “Always have two cakes. Always sing Happy Birthday separately.”

Twin birthday rules: Always have two cakes. Always sing Happy Birthday separately. Thanks to some of my fave twin chicks for the tips @suzeskander @sallycrinis ????

A post shared by Rebecca Judd (@becjudd) on Sep 29, 2017 at 3:19am PDT

The rules are clearly a good thing, because judging by the pic, the little Judds have rather diverse tastes in cake anyway.

One – I’m not even going to try to pretend I can tell them apart – goes the chocolate route. (Classic. Sounds like something a ‘Darcy’ would do.) Meanwhile, the other is all about the vanilla with pink icing.

You do you, boys.

Sydney mum Anne Stephens on having two sets of twins in two years. (Post continues below.)

Earlier on Friday, Judd followed another birthday rule, one that every mother – ever – must adhere to on all of their children’s birthdays: She reminisced about the day they were born.

“This time last year I woke up with an upset tummy thinking I’d eaten something a bit rough the night before but alas, I was in labour,” she wrote on Instagram.

“A quick visit to Dr Len Kliman confirmed the fact. Then [football star husband Chris] made a mad dash across town from a footy finals lunch and scrubbed up (in a suit and tie) for my emergency c-section and voila, 2 healthy babies, who luckily only needed NG feeds and the humidicribs for two days.

“Thanks to my ‘A Team’ for my perfect twins.”