This chapter actually does a good job of adding depth to her character. We confirm that she's a spoiled brat, but uses her cuteness intentionally as weapon. A femme fatale in the making. And also she's not just there to gain information about the MC, whom she might have found interesting - she ultimately wants to play an active role in seducing him and having him killed. This was not clear from the chapter before. But yeah, that last scene is pretty much what we expected, except that now we know it's not just her falling for him suddenly, it's a full reversal of her plans and a surprise to everyone involved.