Most Helpful Guy
I could see how that could be taken as rude. I don't know your mother though (I mean, other than last night) (sorry, I had to). Is she the type to make those sorts of passive aggressive insults? If so, then she was probably doing just that. If not, then she may not have meant it that way.
Most Helpful Girl
She probably was offended by what the person said. Defense mechanism. When people say this, its your job to say I'm beautiful because of her. Hype her up. Her friend was the rude one tbh