Do Anya's classmates know that Yor is her adoptive mother?

I was reading the manga and suddenly realised this is not very clear. Do her classmates (specifically Becky, Damian, Ewen, and Emile – the people always around her) know that Yor isn't her real mother? That she's Anya's second mother? Is there evidence that I have missed for and against this?

In the part right after the bus arc, Damian insults Anya's parents, but it seems like he doesn't know that Yor isn't her real mother.

I find it hard to believe that Swan is the only person who insulted the Forgers for Yor being a second mother. That is probably an attitude in the snobbish, upperclass circles. So, if no one's made it a point to insult her for this, it probably means they don't know.

(Irrelevant to my question, but I am hoping that if this is yet to happen, Damian has matured enough at least not to participate, if he can't defend her.)

I have marked the discussion as a spoiler because if there IS any evidence, it'll probably be from the later Manga chapters.