Being the youngest in the UK, she has had special care in the past 20 years.
Teeny Isabella Evans was born at just 24 weeks on 14 June 2018, weighing just 12 ounces.
Isabella was so small, her tiny hands were smaller than 1p coins.
Watch: Dad of 'miracle baby' proposes on baby's first birthday
But little Isabella, from Bishop's Cleave in Gloucestershire, defied all odds and has just turned one, so her parents Ryan Evans and mum Kym Brown decided to throw a party to mark the special occasion.
And it was a double celebration for the happy couple, as during the party Ryan got down on one knee and asked Kym to marry him.
After the guests sang Happy Birthday and Isabella blew out her candles, Ryan turned to Kym and said: "Obviously it's not just a birthday celebration. It's a celebration of survival really.
"For a long time, we did not think she would get to this point. We are now finally a family. There's only one thing left to make us a real family."
He then got down on one knee in front of his shocked partner and pulled out a diamond ring. How sweet is that, eh?
Oh and Kym said 'yes', in case you were wondering.
The proposal is a lovely end to a tough year for the couple after Isabella was born via an emergency cesarean section weighing less than one pound.
The couple saw their little girl go through two life-saving operations and months of medical scares before she was finally allowed to go home in December.
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Posting on social media after the proposal, a delighted Kym said: "After all we have been through this is the happiest day of my life," before thanking Ryan for being 'an amazing dad' to Isabella.
She added: "Our beautiful little miracle turned one, a huge milestone for such a little fighter.
"I am so, so proud of her, the most amazing person I know. Her smile keeps me going every single day."
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An equally chuffed Ryan said: "I can't wait for us to be man and wife."
Aww! Congratulations guys - and happy birthday Isabella.
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