I found more that weren't accepted than I did that were in the couple minutes I played -- Michelle Obama, Melania Trump, Kate Middleton, Rosa Parks, Marie Curie, Ada Lovelace
Yes, there's quite a lot of names that somehow don't qualify: Margaret Thatcher, Sacagawea, Joan of Arc, Marie Antoinette, yet Madonna and Janet Jackson works just fine.. its really more of a "do you know what pop-culture person I'm thinking of" game.