"Aunt" is already a female term, so all aunts are female aunts (I suppose technically some may be neuter, but that's a somewhat offensive term when applied to people).
My aunt was called Johnmina
Great Aunt
Your brother's (or your sister's) son is your nephew and you are his aunt if you are a female or his uncle if you are a male.
She would be your aunt. Your mother's brothers are called uncles. If your aunt was married to a male, he would also be your uncle. If your aunt was married to a female, she would be your aunt as well.
Your Aunt's niece is you (if you are female), your sister, or your First Cousin.
The female form of the word uncle is aunt.
There is no character called Aunt Dudley. Aunt Petunia's surname is Dursley, her son is called Dudley. Aunt Petunia's sister was called Lily (Evans) Potter.
Sister-in-law describes a female. Brother-in-law describes a male.
Aunt's grandson is called a cousin. Specifically, he is a first cousin if he is the child of your aunt's sibling. If the aunt is a sibling of one of your parents, her grandson is a cousin to you.
Your Father's Sister is called your Aunt.
You are their uncle (if you are male) or aunt (female).
You are your nephew's uncle if you are male, and his aunt if you are female.