What is feminine for teacher?

There isn't a specific word that's the "feminine" equivalent of teacher. "Teacher" is a gender-neutral term.

However, if you're looking for a more formal way to address a female teacher, you could use:

* Ms. [Last name]

* Mrs. [Last name] (if you know she's married)

* Professor [Last name] (if she's a university professor)

* Instructor [Last name] (if she's teaching a specific course)

It's always best to use the title and last name that the teacher prefers.