This is the 11709th most frequent Russian word.
заверила
"Заверила" means "assured" or "confirmed" in English.
Here, 'заверила' means 'assured' as it conveys an expression of comfort or certainty to someone.
Мама заверила меня, что всё будет хорошо.
Mother assured me that everything will be fine.
Here, 'заверила' means 'certified' as it refers to formally confirming the authenticity of a document with a signature.
Она заверила документ своей подписью.
She certified the document with her signature.
Here, 'заверила' again means 'assured,' representing the act of affirming progress to the parents by the teacher.