No, this isn't in the SMS-verse :) My way of writing Anthea is rather simillar no matter where I put her, but Madeleine wouldn't have been quite as calm as Andrea is. Andrea does this primarily for Mycroft while Madeleine would have (and does behind the scenes of the next texting fic) done it for Sherlock.

It's fantastic that Anthea was in series three :D I'm so happy about that! And she got actual, substantial line! "Our agent" not "an agent", she cares/feels responsible for UK secret agents! I'm so excited every time I think about it!