Here's why:
* Neuter nouns refer to things that are neither male nor female. Examples include "table", "chair", "book", and "idea".
* "Female teacher" refers to a person, and specifically a person who is female. Since it refers to a person, it falls under the category of gendered nouns, which are nouns that indicate a specific gender.
Therefore, "female teacher" is a gendered noun, not a neuter noun.