I Failed in Family Tree

Chinese has got different appellation to address our relatives, instead of the easy uncle and auntie in English. That's why most of the time I find it hard to address my grandparents siblings coz my parents won't ask us to address them as simple as uncle/auntie.

Yesternight, one of my friend talked about her auntie (舅母), whom is her mother's brother's wife and how her aunty get along with her grandmother.

(Conversation moderated)
Friend: My auntie has changed. She's my 舅母. *Story goes with her grandma*
Me: Maternal or paternal grandma???
Friend: 舅母 definitely is at 外婆 side la!