My neighbor just told me his son has HIV

So I live in a building with mostly seniors. One of my neighbors just told me that his son is a substance user and has HIV. He told me that he saw him kissing and pda with my other neighbor who is an elderly woman. He said “she probably has it now too”

Should I bring it up to her? I want to make sure she’s aware so she can get tested but I’m not sure ? Also it’s a crime to not tell someone you’re intimate with if you have that