English is possibly the least expressive language in history regarding relationship terminology. It is very common for non-english speakers to prefer idioms that more carefully map what they are thinking of instead of the highly limited and simplistic possibilities of english.
You're saying that it's idiomatic in some languages to say something that translates to "dad's mother-in-law" to refer to one's maternal grandmother?
What is the semantic difference between saying that and simply saying "maternal grandmother" (or just "grandmother")? Does it indicate something along the lines of "my grandmother" while also communicating distance from one's mother, or that one's mother has died?
Do you know of any other interesting relationship semantics that are frequently expressed in other languages, but awkward to say in English?