From my experience, people who care for us will be concerned about what HIV can mean for our lives. So your aunt’s reaction may depend on her knowledge of HIV. I remember when I told my parents, my dad searched the internet for days and studied about HIV. He was ok after that. So you might want to prepare your aunt for the news by desensitising her with HIV information before you disclose. Just start by telling her simple facts and nothing too complicated. See if she responds positively and carry on from there. Good luck!