Mary Anne Spier was always the shyest babysitter, and her weird father always picked out clothes for her and thusly forced her to wear pleated skirts and braids and loafers and bobby socks all the time, which was supposed to be old-fashioned and preppy but really just seemed creepy.
But in one book, Mary Anne broke loose and got a sassy short haircut and started wearing oversized shirts and leggings in wild shades like lavender, and the rest if the BSC was really mean to her because she wasn't a dork anymore or something, even though the BSC was supposed to be about empowerment.
My point is that this girl is Mary Anne. And that everything she's wearing is very bad. Particularly that plaid sweater.