Like in many wealthy American households of the time, it's the lady of the house who is in charge of the servants. Mrs. Lowell is fair and smart, running her house like a business. Margery Cabot Edwards, on the other hand, is a snobby, spoiled rich girl, more than happy to treat all of her household help like dirt. But her maltreatment is a catalyst to get Ceilidh to find work elsewhere, with the Lowells.
When I first started to write The Obolonk Murders, I had no plan and no idea it would turn into three books. At this point, I knew I really needed to finish up already. One thing Untrustworthy has proven, over and over again, is the value of an outline.
In the meantime, the best thing about the Obolonks is the world building. It is potentially the best-built world I have ever created. Hence the sequels. There's plenty of room in this universe.