Katie Turner from Hassocks will be 45 next month and her son Noah is nine months old.
“It’s the classic thing of my thirties were focused on career and that side of things, and I just didn’t happen to meet anyone that I felt I would want to have a child with,” she said.
After she met her partner, who already had a daughter, the couple tried for a baby but after a few years without success, went for IVF and fell pregnant on the second round.
Although Turner was the oldest in her antenatal class by “quite a long shot” she “actually had a pretty great pregnancy”.
However, she found it difficult to relax as “you were just kind of gently always reminded that the risks are higher when you’re older”.
She now feels “very lucky” to have her son and said it had been a “wonderful experience”.
“I’d be lying if I said being the age I am doesn’t play on my mind,” she added.
“I sort of do the mental maths constantly of like, when he’s this age, I’ll be this age.”
But she says she has noticed she is generally less anxious than younger mums.
“I’ve been through enough to know there are sometimes bigger things to worry about, you know?”
Clarke said that her age does not matter to her, or her daughter.
“It’s how you feel in yourself. I’m fit, I have a very young outlook on my life. I’ve not once felt like the oldest mum at the school gates,” she said.
Having watched her raise her daughter, Clarke said her family were now very proud of her and they are back together as a “family unit”.
Follow BBC Sussex on Facebook, external, on X, external, and on Instagram, external, and listen to BBC Radio Sussex on Sounds. Send your story ideas to southeasttoday@bbc.co.uk, or WhatsApp us on 08081 002250.