Non-jewish wearing star of david?

I’m not sure if this is in the right place, if not then please let me know and i’ll change it.

I myself am not Jewish, however I do have a jewish grandmother who i love dearly. Sadly, she is starting to get really sick and i am scared for her health. Everyday for years she has worn the same necklace with the star of david on it, she loves educating the family on anything to do with judaism and i love to listen to her. She also has a massive portrait of her grandmother (my great great grandmother) that she stares at all the time because her grandparents were sadly murdered due to being jewish. Because of her ill health, we’re starting to think she wont last much longer, and I’d like to honor her, her love for her religion, and our family heritage. My first thought was perhaps something like her necklace, but then i had thought about how i may have been mistaken for a jewish person by anyone. Maybe something more discreet? I would love to hear any suggestions or knowledge anyone has to offer.