So I put my plans to be a lawyer on hold and swapped nights out for evenings spent flicking through the Mothercare catalogue. Gradually, I started to get used to the idea of being a teenage mum, especially when we found out I was carrying a little girl.

But at five months, another bombshell. Doctors discovered our daughter’s bowel had formed on the outside of her body. I cradled my bump protectively as doctors assured us that it could be corrected with surgery after the birth.

And then, just as I’d got my head around that, more tests revealed her brain was dotted with dangerous cysts. I wept when the consultant explained that it was unlikely my little girl would ever really know me.

But despite everything, I was determined to be the best mum possible. And when Isabelle was born at 37 weeks weighing just 4lb 13oz, it was love at first sight.

As she was whisked away for the four-hour surgery needed to correct her bowel, I watched the other mums on the ward cuddling their babies and my heart ached with emptiness. Why me? Why did my baby have to be different? I didn’t even get to hold her until she was three weeks old.

Still, Simon and I stayed by her bedside, learning to wash, bath and feed her as each day she grew stronger.

‘Come on, darling,’ I begged as her tiny fingers curled around my thumb. ‘Show them you can do this.’

She’d been born with a rare brain condition called Schizencephali. Cysts had formed on her brain leaving her blind and mentally disabled. She suffered terrible fits too. But despite everything she was a gorgeous baby.

She was nearly three months old when we finally got to take her home.
We were delighted. But just a day later she stopped breathing and was rushed back in. It became a familiar pattern for the next five months.

When Isabelle turned seven months, Simon and I got married with her as our bridesmaid. But the strain of caring for her was too much and we split up just two weeks later. Looking back, it had probably been coming for months.

Now it was just the two of us, I tried to make life as lovely as possible for Isabelle, staying with her in hospital and a hospice for respite care and taking her out when she was well enough.

It was far from plain sailing. At Christmas her body started to shut down and we nearly lost her but doctors managed to bring her back and dosed up with drugs she somehow pulled through.

I knew the odds were stacked against her but slowly, Isabelle developed her own little personality. She was so ticklish and would giggle like mad when I tickled her up and down back. She started to smile when I spoke and I swore she started to recognise my nickname for her – ‘Bumpy’ – from when I bounced her up and down on my knee.

But then, just weeks before her second birthday she’d developed this chest infection and myself and my new boyfriend Steve had taken her back into hospital. All week I’d been told she was getting better and would be coming home. But now, this…

I wouldn’t, couldn’t let myself think it was the end but as we pulled into Peterborough District Hospital and a nurse met me in reception, I knew things were serious.

I was ushered into the Parent’s Room and a doctor took my hand.

‘I’m afraid Isabelle has had another fit. She stopped breathing for half an hour,’ they explained. ‘We’ve tried to stablise her…’ An ambulance was being prepared to rush her to a better equipped hospital.

Blinking back tears I called my parents and sister and Isabelle’s dad and asked them to get here as soon they could. Then the nurse took me into see her.

Lying there on a ventilator with her eyes taped shut she was so tiny and frail. She didn’t look like my Isabelle any more. And in that moment I knew I’d lost her.

As the nurses rushed around trying to organise an ambulance to take her to a more specialist hospital, Mum took my hand. ‘You know what you’ve got to do love,’ she said. We’d talked about it a million times before.

And looking over at Isabelle I knew it was time. Like any mum I wanted my daughter to be happy and free from pain. But watching Isabelle being pumped full of medicine just to keep her breathing wasn’t right. As much as the thought of saying goodbye to her killed me, it wasn’t fair to keep her alive at any cost. Isabelle had suffered enough and as heart breaking as it would be to lose her, I couldn’t see her suffer any more.

I rang the buzzer next to her bed, asked to speak to the consultant. And when he arrived:

‘Cancel the ambulance. I don’t want you to do anything more.’

‘Are you sure?’ he asked gravely.

I nodded. I’d never been more sure of anything. I wanted my little girl to die.

He nodded. And when he told me that Isabelle had less than a one per cent chance of ever coming off the ventilator I knew without a doubt I’d made the right decision. Simon agreed with my wishes.

All the tubes and clips keeping Isabelle alive were removed and she was placed in my arms. ‘I love you,’ I whispered. And just three minutes later she was gone.

As the pain hit me I had to physically stop myself from screaming out that I’d made a mistake and wanted her back. But as Mum gently led me from the room I knew I’d done the best thing for Isabelle by letting her go.

Nine days later she was buried in a tiny white casket edged in gold – just as I’d planned it. The day passed in a blur.

Everyone kept telling me it was the ultimate sacrifice a mother could make – putting my own feelings away to do the best for my girl. But still I tortured myself thinking Isabelle would still be alive now if I hadn’t chosen to let her die.

Those next months, I tried hard to move on but after caring for Isabelle 24 hours a day it seemed my whole purpose of living was gone. I was desperate to talk about Isabelle but it made others feel uncomfortable. Eventually Steve and I split up.

Alone in her room, which I’d kept just as it was, I’d sit and cuddle her favourite orange aardvark toy, go through her things and look at photos.

Of course there were times I wished I hadn’t made that decision, if only I could hold her again one more time….

‘It’s never going to get easier, is it?’ I’d torture myself, weeping into her blanket.

But slowly, it did.

And now, 18 months after her death, I finally feel like I’ve turned a corner. I’ve got together with an old friend, James, who knew Isabelle, and we have a beautiful six-month-old son, Joshua.

I was petrified when I first found out I was pregnant. What if this baby had the same condition as Isabelle, I fretted. Schizencephali can be hereditary. But thankfully, everything was fine.

And when little Joshua was born last September weighing 9lb 1oz and looked up at me, it was like looking into his sister’s big blue eyes all over again.

‘Oh, Isabelle would have loved you,’ I told him.

Even though he’s too young to understand I still talk to him about her and show him her photos. Isabelle was a very special little girl and although it was my decision to end her life I’m determined that she’ll live on in all of ours.