The 47-year-old has taken to Instagram to reminisce about motherhood.
'How I will miss this blonde bundle of love who ventured off 8 hours away to start uni,' she revealed.
'Where did the years go... my heart swells but so do my tear ducts.
'Quite pathetic but tonight I’m lying on his bed reminiscing about being gifted the role of raising such a wonderful young man.'
'A mother’s love for her children, as you know, is fierce and unconditional. It’s his time to fly and if he waivers he knows I’ll be waiting arms open.'
Thorburn shares three children, Jackson, 19, Ava, 13, and River, 12, with ex husband Karl Stefanovic.