Sue Tollefsen, 61, revealed she was recently left unable to care for Freya for weeks after contracting a blood infection that left her incapacitated over Christmas.
The retired teacher, who became a mother four years ago, said the experience of her illness made her realise she may not be able to see her daughter grow up.
She also now agrees that 50 should be the “cut-off” age limit for becoming a parent.
She said: “It’s so true that you learn from your mistakes, and my mistake was not having her sooner.
“I was so ill, I literally thought I was dying. I kept thinking about Freya - and for the first time, I realised I might not be there for her any more.
“If I’m completely honest, my experience has taught me that 50 should probably be the cut-off limit for having children.
“But, until you have them, it’s almost impossible to appreciate that.”
Miss Tollefsen, of Harold’s Wood, Essex, caused controversy in 2008 when she had her daughter via IVF, using sperm from her then partner Nick Mayer and a donor egg.
At the time, she defended her choice and pointed out that Mr Mayer was 11 years her junior and would therefore be around to care for their daughter during all of her childhood.
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But critics condemned the couple’s decision, saying she was too old to become a mother. She has since also faced a backlash from other parents.
In an interview with Closer magazine, she revealed how one mother at her daughter’s crèche had told her she was “selfish”.
She said: “I was in tears, it made me feel very vulnerable. Once, I took Freya to see a health visitor and she thought Freya was my granddaughter. I was so embarrassed.”
Miss Tollefsen also revealed the strain of her day-to-day routine as a single mother. She split from Mr Mayer, 49, a warehouse manager, last year.
She said: “At my age, I get exhausted easily – especially since I’ve been ill.
“I was 57 when I had Freya, but I felt very energetic and able to cope. I thought I would feel fit and healthy forever.
“I hope I live to see Freya go to university and get married and have a family of her own. That’s my only wish now.”
Miss Tollefsen became pregnant in June 2007. She and Mr Mayer spent £15,000 on fertility treatment in Russia after they were turned away from British clinics because of her age.
Government guidelines recommend doctors do not offer IVF to women over 40 on the NHS, and private clinics will generally refuse to treat women older than 50.
Freya was born in March 2008 by Caesarean section. The four-year-old stays with Mr Mayer every other weekend, and he looked after her when her mother was ill.