Ling and her two-year-old boy are just like any other mother and son, except in one regard. One day, when he gets older, Ling will have to sit down with her son and explain that she carries the virus that can lead to Aids.
It is not a conversation she is used to having: she has not even told her own mother about her condition in the decade since she was diagnosed with HIV. Instead, her mother wondered why Ling and her husband were not giving her grandchildren.
"We said we didn't have the financial ability, and our home wasn't big enough," said Ling, who prefers not to give her real name or more details of her life.
Mother-to-child transmission was once one of the main ways the virus spread, but antiretroviral medication has given women with HIV the chance to have children.
The condition almost cost Ling her life soon after the diagnosis, but she has taken the drugs diligently ever since.
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Four years ago, her doctor gave her the "green light" for pregnancy as the virus had been cleared from her bloodstream.
"It was amazing. I hadn't thought I could have children. I have the disease, and people think it's serious, though I personally don't think so," Ling said.
She and her husband, whom she married 12 years ago, had wanted children, but had not given the matter much thought.
"He understands about the disease and didn't want our children to have it too," she said.
Ling became pregnant several months after being given the go-ahead by her doctor. "I was so happy that day. I told everyone about it," she said.
As a member of the Society for Aids Care, a nurse from the group helped Ling liaise with her HIV doctors, obstetricians, and after the baby's birth, paediatricians who administered preventative medication and carried out precautionary tests on her son.
"I was confident all along that my baby would not be infected," she said. Nonetheless, she chose to undergo a caesarean section to minimise the risk of infection during birth.
"My whole way of living changed after having a child; it became more fulfilling," she said.
And she is determined that one day her son will know of the challenges his mother faced to bring him into the world.
"I'll tell him. Whether or not he accepts it would be another matter. He has the right to know," she said. "But I'm worried that when he's at school, he might tell his classmates and he'll be discriminated against. I'll tell him when he understands more about society."
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Society for Aids Care programme director Esther Choi Siu-fong says many HIV carriers feel pressured because they feel the need to keep their condition secret from people around them.
"It's a big relief for many of them to tell their children," Choi said. "We don't force them, but we encourage them."
But there is one person Ling will never tell.
"My elderly mother would not understand it," Ling said. "She's stubborn. She would think I must have done something bad. She wouldn't say it but she'd think that way. I don't want her to have this bad impression of me."