I think its safe to say that Mrs. Martha Stone had a good working relationship with her maid Amelia Icard. According to her biography on the website, she left her a large sum of cash and personal possessions to her in her will.
As for Millie Brown, gloating over the Allison's death (which is how it comes off) is despicable. They must have been some really horrible employers to feel nothing for them or their families.
I've read in one of my books that Maria Penasco's maid had a cabin across the hall from the "main" cabin. Perhaps the grandest rooms had just such a smaller room close by, so the couple/family could have privacy but the maid would be handy.