1) Is "Pronouns have seven kinds" correct?
No, there several different types of pronoun.
2) She herself (emphatic pronoun) has done this. Can "herself" still be called "reflexive pronoun" in this sentence?
Yes, it’s a reflexive pronoun.
3) Are "former, latter, later, such" also "demonstrative pronoun"?
The former, the latter and such can function as pronouns.
4) Reciprocal pronoun - each other, one another - Please explain this kind of pronoun.
The reciprocal pronouns `each other' and `one another' are used to indicate that people do the same thing, feel the same way, or have the same relationship.
5) Is "how" an interrogative or relative pronoun?
How is an adverb, not a pronoun.
Student or Learner