‘Rest in peace little man, we love you forever,’ Alfie’s father, Leigh, wrote on Instagram in tribute to the little boy.
Before she died, Sara had penned an emotional letter to Alfie – who was then 18 months – and his brother, Hugh, then three.
‘I won't be around to see you grow up. It's a hard thing to say and even harder to face,’ the mum started her letter, which she shared with the New Daily and gave New Idea permission to republish.
‘I know your Dad, and our village of family and friends, will keep me alive for you as much as they can, but there are some things I want you to hear from me,’ she went on.
‘Don't be afraid of expressing your emotions. I will never tire of hearing 'I love you' from Leigh, you boys, my family, friends.
‘Love hard. As they say, it is better to have loved and lost, than never to have loved at all. That's how I feel about you both.
'Heartbroken doesn't come close to describing the pain I feel at not being in your lives in the future, but I would never change or forego the time we have spent together and the immense joy you have brought me,' the loving mum continued.
'You are without a doubt my proudest accomplishments.
‘Your Dad is the most admirable, courageous man I have ever known,’ she went on. ‘He is my companion, my rock, my everything. He has shown true grit in the face of our adversities, and without him beside me I would have crumbled.
‘I will be forever grateful for the time we spent together, the memories we created, the love we shared. It was always him. Always will be. Love, Mum’