The noun 'uncle' is a gender specific noun for a male relative.
The corresponding gender specific noun for a female relative is aunt.
The female form of the word uncle is aunt.
ant
Sister-in-law describes a female. Brother-in-law describes a male.
The female nephew is called the neice.
Your father's brother is your uncle. You are his niece (if you are female) or his nephew (if you are male).
Filipino translation of uncle: tiyo
Your relation to your mums uncle is GREAT uncle. You're welcome! 
Grandmother. "Brother", "uncle" and "father" are all male. "Grandmother" is female.
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.
Guessing you mean the wife/sister of a great uncle, which would be great auntie.
Your mother's uncle, whether maternal or paternal, is your great uncle. You are his great nephew if you are male, and his great niece if you are female.