Displaying a generosity of spirit in rank contrast to the apparent callousness of the Australian couple who abandoned a Down's syndrome baby born to a Thai surrogate mother, the young woman has declined offers to adopt him, announcing that she intends to bring him up herself.

The offers – along with donations of, as of last night, more than A$164,000 (£90,780) – were made by well-wishers following publicity about the plight of six-month-old Gammy, who was spurned by his biological parents after Pattharamon Janbua, 21, gave birth to twins. The couple, who have not been named, took Gammy's healthy twin sister back to Australia.

Their actions have sparked revulsion around the world, and prompted Thai authorities to crack down on the previously unregulated surrogacy industry. With commercial surrogacy banned at home, hundreds of Australian couples travel to Thailand each year to arrange surrogate births through local clinics and agents.

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Ms Janbua said that, after her experience, she would advise no Thai woman to "get into this business". She told Australia's Fairfax Media that her family was struggling to pay off debts last year when she was approached by an agent and offered the equivalent of £6,477 to carry a baby for the couple, who are believed to live in Western Australia.

Three months later, after a doctor implanted the Australian woman's fertilised egg into her uterus, she discovered she was expecting twins. The agent promised her an additional £926 for the second baby. But four months into the pregnancy, routine checks established that one of the twins had Down's syndrome.

On learning this, the parents – through the agent – urged her to have an abortion. "But I didn't agree, because I am afraid of sin," she told Fairfax, referring to her Buddhist beliefs. Then, when the twins were born, the agent took the girl, leaving the boy with her. She never met the parents.

The case has come to light at a time when Gammy is seriously ill in hospital, with a lung infection and a congenital heart condition that requires surgery. Ms Janbua – who has two children of her own, aged six and three, said she was overwhelmed by the donations that have flooded in for Gammy's medical bills and care.

"I'll share some of the money to help other babies who have Down's syndrome and orphan children," she said. Explaining her decision to bring up the baby, she said: "I'll take care of Gammy on my own. I'll not give my baby to anybody … I don't wish him to be the smart boy or intelligent person … I just want to see him as a good man. Whatever he wants to be, I will always support him, my boy."

Ms Janbua, who lives in a poor village 56 miles south of Bangkok, also said she forgave Gammy's parents. "I wish they will love my baby … I forgive them for everything … I don't really think too much about the Australian couple. I can't blame them. I don't feel upset or angry about them any more. They might have their own problems, too."

On the fundraising site, though, people expressed horror at the couple's actions, with one man, Towe-Karin Iversen Saleh, writing that "I'm sitting here in Norway … and cannot believe what I read. What kind of people do such an act[?]" Another, Erica Choi, wrote: "Gammy is such a beautiful baby! Shame on his biological parents!"

An Australian charity, Hands Across the Water, has stepped in and was yesterday preparing to have Gammy transferred to a private hospital in Bangkok. The charity will also keep the donated funds in trust.

With commercial surrogacy now illegal in Thailand, many Australian couples have been left in limbo, desperately trying to find out whether they will be able to take home babies currently being carried by Thai surrogates.