Ms Hurst described her son as confident and outgoing
Mothers who breastfeed older children face "cultural" opposition despite no evidence that the practice is harmful, a leading parents' charity has said.
The comments came after a mother from South Yorkshire defended her decision to continue breastfeeding her five-year-old son Jonathan.
Amanda Hurst, from Barnsley, said she had originally intended to stop at six months but carrying on "became a natural thing".
National Childbirth Trust (NCT) breastfeeding counsellor Heather Welford said: "There is no evidence that breastfeeding children at any age is in any way harmful to the mother or child, either psychologically or physically.
"In our 21st century European culture it is very unusual, but it's not unusual historically or in other countries.
"Sometimes you will get psychologists talking about it and saying it may be detrimental, but I don't think they're aware of all the facts.
"You even get some healthcare professionals who will advise women to stop breastfeeding after six months, telling them there's no goodness left in the milk.
"That's not right, the milk remains as healthy."
Ms Hurst said her son was confident and outgoing and had chosen to continue feeding.
"I know I'm doing the right thing and I'm a firm believer in children making their own choices," she said.
She told the BBC that until recently nobody had been aware that she was still breastfeeding Jonathan as he had decided to stop doing it in public when he was three years old.
"We just never stopped," Ms Hurst said.
"Once I gave birth to Jonathan and I started breastfeeding, I thought we'll just get to six months and then I thought we'll go to a year and then it never stopped.
"And here I am five years on. It became a natural thing.
"I'm a firm believer that Jonathan should choose his own path in life," she said.
Ms Hurst said breastfeeding Jonathan would stop when he lost the ability to suckle as his milk teeth fell out.
She added: "I know I'm doing the right thing and I'm a firm believer in children having their own choices and in doing what's right for you and your family and I made those choices for my family."
Ms Welford said: "That mother is fairly typical of women who are breastfeeding children at older ages.
"She doesn't do it very often and it's something that will fade away of its own accord.
"Women do not set out when they have a baby and say 'I am going to breastfeed until my child is five years old', it just sort of happens."