Sydelle Pulaski reveals that she took her shorthand notes in Polish. What does this reveal about her?

Taking her notes in shorthand reveals Sydelle's deep mistrust of the people around her. She doesn't trust them, and she keeps her notes in a language that only she can read.

“You wouldn’t understand, Angela, you don’t know what it’s like to be.…” Her voice broke. She paused then lashed out at her enemies, all of them. “Who cares a fig about Sydelle Pulaski? Nobody, that’s who. I’m no fool, you know. I knew I couldn’t trust any one of you. You can’t read my shorthand because I wrote in Polish.”