Here's why:
* Relative pronouns connect a dependent clause (a clause that cannot stand alone) to an independent clause (a clause that can stand alone). They also act as the subject or object within the dependent clause.
* In this case, "who" connects the dependent clause "who inspired her students" to the independent clause "Mrs Godot was a teacher."
* "Who" also acts as the subject of the dependent clause ("who inspired her students").
Let me know if you'd like more examples!