Juliet sends several short letters to Sidney, jokingly asking if he's not responding to her letters because of Mark Reynolds. Finally, Juliet sends a longer letter explaining that she went to Sidney's office, met with Sidney's secretary, Miss Tilley, and discovered that he left for Australia. Miss Tilley coolly promised to forward letters. Juliet says that she knows Sidney is in Australia to see Piers Langley. She reminds Sidney that she is capable of being discreet.
Sidney will later reveal that he's gay; because of this, Juliet's mention that she can be discreet suggests that Piers may be Sidney's love interest. Sidney's secrecy indicates that he knows that a public relationship with Piers wouldn't go over well, given that society still supports heterosexual marriage only.
Juliet says she liked Sidney's old secretary better than Miss Tilley, and explains that she met Mark Reynolds. She says that Mark is perfectly fine and hasn't tried to poach her, and she even thinks that he and Sidney could be friends. She mentions that her Times article is going well and says she's made new friends on Guernsey.
Miss Tilly, like Bella Taunton, prefers to stick to rules and regulations rather than treat people like multifaceted and feeling people—which explains why Juliet doesn't like her, given Juliet's desire to treat everyone with kindness and empathy.