At first I was wondering if that thought process was warranted, so I skimmed through the previous chapter again.
Definitely warranted. In other cases, being friendly to the maids would be a better supervisor decision, but in this case, she has no supervisory power if the maids weren't acknowledging her before. Still a bit out of character for them to go apologize to her, unless she was interpretting their previous actions incorrectly; doesn't seem likely of that though.