This is the 11938th most frequent Russian word.
заступилась
"Stood up for" or "defended."
The word 'заступилась' here means 'stood up for', indicating that the person defended or supported her friend during a conflict or discussion.
Она заступилась за своего друга в споре.
She stood up for her friend in an argument.
In this sentence, 'заступилась' conveys 'interceded on behalf of', showing that the teacher advocated for the student in an official capacity.
Учительница заступилась за ученика перед директором.
The teacher interceded on behalf of the student to the principal.
Here, 'заступилась' implies 'defended' in the sense of protecting or standing up for someone against unfair treatment.