Paida Mutopo was nervous meeting Prince Harry and Meghan Markle.
The 21-year-old, who was born with HIV, told them about herself during their first official engagement together in Nottingham on Friday.
"I never thought the day would come when someone as high-profile as Prince Harry would be supporting this cause," she tells Newsbeat.
"It means a lot to me that he is actually taking his time to go and work with people affected by this disease."
Paida chatted to the couple as they visited Nottingham Contemporary Exhibition Centre for an event to mark World Aids Day.
"I still can't believe it's real," says Paida, who has been recognised for her work in raising awareness of HIV, which attacks the immune system.
"I was so nervous until they started talking to me and they actually recognised my work.
"They're a lovely couple and I know that they're passionate about raising awareness and trying to tackle the stigma surrounding HIV."
"I didn't get diagnosed until I was 10. I became ill and my mum didn't know what was wrong.
"So she got me tested. That's when we found out that both me and my mum were HIV positive."
Without treatment, HIV gradually destroys the immune system, meaning it's much harder to fight off infection. In some cases Aids can develop.
"World Aids Day really means a lot to me," says Paida, from Manchester.
"I've got a few family members who've lost their lives due to the stigma of not wanting to get tested for HIV and not wanting to take tablets."
About 35 million people have died of HIV-related illness worldwide since the virus was first identified in the early 1980s, according to World Health Organization (WHO).
"When I was first diagnosed I used to take a lot of medication, 10 tablets a day. It was overwhelming.
"My immune system had gone really down because for years I didn't know I was HIV positive."
Because of medical advances, today around 37 million HIV positive people like Paida worldwide are living healthy lives, according to WHO.
"Now I'm on three tablets a day and my HIV status is undetectable," she says.
"It's controlled now, and the chances of me passing it on are as good as [not having it] any more because of that medication I've been taking for so many years."
Last year she gave birth to a son, Kai, who doesn't have the virus.