Re: CONVERSATIONS.
I presume that Margo probably sat somewhere near or close enough that she could talk to T'Challa. If so, then she probably chatted about various thing, and probably did NOT bite her tongue. She kind of doesn't have a filter there. Like she tries, but sometimes the stuff she thinks to say "nicer" comes out worse so.
She let other people answer Fillory questions if they wanted to, especially Quentin who should really be the Fillory ambassador (nevermind that it was Margo who used to pretend to be an ambassador for Fillory when she was younger). She'd have also have introduced Eliot as the High King too.