A little bit of a character/scene spoiler warning (not a crucial plot spoiler).
I think I would have enjoyed this more if the main character's love interest hadn't drugged her without her consent. I realize it wasn't for any malicious purpose, but even so, it made it difficult to understand her interest in him after that point, especially given her more modern and feminist beliefs. I suppose the author was trying to make him daring and a bit dangerous but I think there are ways to do that without violating consent like that, especially given that it served no purpose for the plot.
I am still debating whether to carry on with the series or not. With this one exception, I did enjoy the characters, the witty dialogue, and even the plot, although I must say I called whodunit from very early on (though I admit for not the reasons I originally thought). I am a bit curious to see where Lady Julia goes from here.