I’m still looking for reference material that charts out all the different titles of people in your family. I don’t think I’ll ever find one, either.
I’ve never taken time to learn all those titles, and nobody deserves a black belt in Mandarin unless they know the titles inside and out. The differences basically boil down to “Mom’s side” vs. “Dad’s side”, “Mom’s side” is easier because it goes into less specifics, right (重男輕女 mentality)? So if you’re interested, let’s figure it all out and I’ll put it in a neat little chart.
all Mom’s brothers: 舅父 and their wives: 舅母
Dad’s big brothers: 伯父 and their wives:伯母
Dad’s little brothers: 叔父 and their wives: 嬸母
So the only tricky one here is “Dad’s little brother’s wife”, since you might think it should be “叔母”, but ah-hah! You are mistaken. A Black Belt would know that 叔父 is married to 嬸母