Carol Niven, 57, from Larkhall, South Lanarkshire explains...
Since they were tiny, my daughters have always been close.
Lisa, now 26, the eldest, was protective over baby sister Laura, 21. She held her hand on her first day of school and helped her do her hair.
As adults they had their own styles and personalities. But not much else changed, really. They only lived 10 minutes apart and, over the years, had stayed best friends.
So, when Laura collapsed at her job in a bank, I let Lisa know as soon as I was told.
‘The doctors think it might be appendicitis,’ I said. ‘She’s been rushed to hospital.’
Within minutes, Lisa was on her way to Wishaw General Hospital.
We sat, worried sick, in the waiting room as Laura had scans and tests.
After hours, she came out looking pale…
‘You’re not going to believe this, Mum,’ she whispered. ‘I’m pregnant!’
At first they thought it was ectopic, but luckily it wasn’t.
It wasn’t appendicitis – but my grandchild!
At first I was relieved, then speechless that my baby girl was having a baby!
Laura and her husband Edward hadn’t been planning to start a family just yet.
But it was a wonderful surprise.
‘You’ll make an amazing mother,’ I told her.
Lisa was over the moon, too.
She already had Orla, her 3-year-old daughter with partner Scott.
We celebrated all night, but the surprises didn’t end there…
The next day, I got a call from Lisa.
‘You’ll never believe it, Mum,’ she said.
Well, that sounded familiar…
‘I’m pregnant!’ I was gobsmacked. Another grandchild!
Her baby was due 10 days after Laura’s.
‘I’d better get saving,’ I joked.
The girls really loved fussing over each other. They shared tips, baby books and gave each other advice.
Lisa helped to calm Laura’s worries when she had morning sickness. After all, she’d been through it before.
It was the icing on the cake when they found out they were both expecting boys!
And I loved buying them matching outfits.
‘History’s repeating itself!’ I laughed to my husband Craig, 52.
On 7 February, Laura was rushed into hospital to be induced at 10 days overdue.
Her baby was back to back, meaning it was lying on her spine, slowing down the birth.
I held her hand tight, but in the back of my mind I couldn’t stop thinking about Lisa, too.
As Laura slept, I quickly called her sister.
‘I think I’m in labour. I’m having contractions,’ she said.
I told her she should come to the hospital right away.
As I sat with Laura, Craig leapt out of his seat after a call.
‘Lisa’s giving birth in the car!’ he shouted.
He drove home to look after Orla, and by 8pm, Lisa was wheeled onto the ward. Total pandemonium!
Luckily, they were only doors apart.
It was good exercise for me running between the two…
As soon as I was in one of their rooms, my other daughter would start screaming.
I was like a headless chicken!
Poor Laura was having a traumatic time, though, so I stayed with her longer.
As I couldn’t hear Lisa’s screams, I assumed she must be asleep.
Suddenly, at 11pm, an emergency alarm went off.
I jumped out of my skin.
‘Is that my daughter?’ I panicked.
‘Don’t worry, it’s not Lisa,’ the midwife said.
Five minutes later, she came back in.
‘Lisa needs you,’ she said.
She had a big smile on her face.
Opening the door to Lisa’s room, my knees gave way.
‘Look what I’ve done, Mum,’ she announced, holding a tiny bundle in her arms.
I have to say, there wasn’t a dry eye in the room. I was so proud.
‘He’s called Thomas,’ she smiled. ‘But I need to go and see Laura, now.’
Always the bossy one!
Amazingly, she showered and walked with Thomas to see her sister.
Laura was still in labour, but lay cuddling and cooing over little Thomas.
Lisa was discharged, but Laura was kept in overnight.
I held her hand the whole time.
Finally, at 11.30am on 8 February, baby Craig James, or CJ, was born by Caesarean.
He had dark hair, exactly like his cousin. Born only 12 hours before.
Now both the boys are absolutely beautiful and thriving. And so are their mums.
Turns out, the girls defied 125,000 to one odds going into labour at the same time.
And I’m the proudest double granny in the world!
Carol has donated her fee to Brightest Star, a charity supporting bereaved families.