Darjeeling is well known for her calm and chivalrous personality. She has a great many personal mottos, most of which are lifted from famous poets, playwrights and authors. Two examples of these are: "No matter how fast we go, or no matter how many hits we take, I will never spill my tea." and "An Englishwoman abandons her morals in love and war" (a variation of the popular proverb "All's fair in love and war.") She's also shown to really like drinking tea, and is nicknamed after the Darjeeling tea (like all other "foreign-themed" characters in the show, she's actually Japanese) like most people in her school whose nicknames are based on different kinds of tea. She tends to use puzzling idioms a lot, some of which even Orange Pekoe, her trusted lieutenant and loader, and apparent best friend, can't understand.

In the spin-off manga Girls und Panzer - Motto Love Love Sakusen desu!, she's shown to be very easily influenced by novels and media, going as far as to trying to recreate a scene in a love novel with Orange Pekoe and posing as a maid while offering a (horrendous) maid service to her teammates Orange Pekoe and Assam, as well as the Anglerfish Team, after being influenced by the popular anime line "Do you want a bath? Do you want dinner? Or... Darjeeling?". She's also shown to have a strong obsession of weird things as long as they're symbolically English, like eel jelly or "driving" a coach. She is also shown to be quite vague at times, such as asking questions like "what is lottery?" and referring an amusement corner as paradise. However, of course, these character traits may or may not be canon.