>>281153215
I would just toss it up to her not knowing rather than intentionally leaving it out. It might just be something left unmentioned in any books (translated into Japanese and available in the early 2000s) that addressed the Victorian servant hierarchy. We have easily accessible information now via the internet and MTL, and at the very least, when she drew them more recently in Otoyo, she knew maids didn't quite have uniforms yet in the mid-1800s. Her drawing the corsets as underbust in this chapter shows a lack of knowledge.

Kuroshitsuji was similar as it started pretty anachronistic (still is, but in a more targeted way + the the traces of the earlier stuff), but now has a researcher or two credited at the end of the volumes.