The next day she pacified the teacher explaining her the reason for the previous day's leave.

Quietened : make or become quiet and calm.
Silenced : cause to become silent; prohibit or prevent from speaking.
Pleased : feeling or showing pleasure and satisfaction, especially at an event or a situation.
Flattered : lavish praise and compliments on (someone), often insincerely and with the aim of furthering one's own interests.
Pacified : quell the anger, agitation, or excitement of.

Synonym of Pacified is Quietened