How does Hattie prove her loyalty to the Archers in the play, The Verge?

Hattie, the Archer's maid, is loyal to the family and gets very concerned whenever she feels something is amiss. When she notices Mr. Archer talking heatedly with Mr. Demming, she becomes very upset and tries to get Anthony to intervene. She also serves an important function at the beginning of Act III when she reports what occurred the previous night and what she witnessed during the conversation between Mr. Archer and Mr. Demming.