I haven't heard that but I think I might disassociate myself from anyone who spoke about the kids in a weird manner like that! Sometimes people will refer to the girls as Miss Ruby or Miss Vivian, but only if they're being playful and talking to them directly, like if one of them is dressed up fancy. I think their ballet teacher used to do that sometimes. But not like what you are saying. I think I'm baffled by the concept though.