To be honest, this chapter has me convinced that Edward was not the one spying on Kate in Ch 48. Here he is shown to be willing to risk inviting Maryrose (and potentially taking a hit to his reputation when she fails the unification) based on the possibility that she may be a dissident and that he might make her talk. If Edward had heard Kate's conversation with Emilyko in 48, he would have already grabbed her to try and make her spill how she knows what she knows. While Edward may seem like a calm chess-master type, that is actually just an act that he likes to put on. He is actually a bully with a need to constantly assert his dominance over others.
The spying sequence: https://mangadex.org/chapter/1010636/6, we see Kate being spied on by a small black form, likely a clinger under someone's control or a morph. https://mangadex.org/chapter/1010636/7, we then see Edward giving out orders with a smug face. However, Edward almost always has a smug face, so him having this expression doesn't mean much.