"When I saw Oliver’s head crowning, a flood of emotions over took me," Overton told The Huffington Post UK.
"I was in awe of this miracle before me, I felt immense gratitude for my surrogate, Cydnee, I felt full of love for this child and our family, and I was relieved.
"Oliver was three years in the making."
Overton was told by a doctor in 2005 that she had fibroid tumours - her muscles had come together to form a "knot" within the uterus.
A year later she had the tumours from her uterus removed. She was encouraged to try for a baby within five years and did so, having her first son Dillon aged 39.
But when Overton tried to fall pregnant with her second child, the fibroids in her uterus had grown back and she found it difficult to conceive, so she decided to turn to surrogacy.
On 27 July 2015, Overton's surrogate mother confirmed she was pregnant, after a three-year wait.