In Chapter 9 of Andrew Clements' Frindle, Mrs. Margaret Chatham, principle of Lincoln Elementary School, schedules a conference with Nick and his parents at Nick's house. During the conference, the narrator notes several character and physical traits of Mrs. Chatham.
One physical trait the narrator notes is that she is an extremely tall and wide person. She is "as tall as Nick's dad, with wide shoulders," which is significant since the narrator also notes that Nick's dad was a football linebacker in college (p. 47). She is also dressed in a "long black raincoat" and "red silk scarf" (p. 47). Later, Nick feels that he and Mrs. Granger are in a chess match, and Mrs. Chatham, in her black coat, represents the black queen on the chessboard.
As for character traits, Mrs. Chatham comes across as rather stern; she sternly believes she must uphold her own perspective about what is right in order to protect the school. She comes off as stern when she refuses to greet Nick with a smile. She also comes off as stern by refusing any hospitality. She refuses hospitality by refusing to remove her coat, only her scarf, and by declining Mrs. Allen's offer of "coffee and banana bread" (p. 50).
Yet, though she sternly upholds her own view that Nick must stop using the word frindle to protect the school, she also demonstrates that she has an understanding nature, which is seen when she does her best to understand everyone's perspective. She demonstrates her understanding nature when she replies to Mrs. Allen's comment that the whole school seems to be making a lot of silly fuss over nothing, saying, "Yes, I suppose it does seem silly" (p. 48). Yet, regardless of agreeing that the situation is silly, Mrs. Chatham also upholds her belief that insisting on using a made-up word shows a "lack of respect for authority" (p. 48). By the end of the conference, no issues have really been resolved, and Mrs. Chatham accepts that, being satisfied to at least have had her say and spoken on behalf of Mrs. Granger.