from/on both sides

Is the sentence below ok?

I get my good looks from my mother's side.



Yes, that's what is commonly said.

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Thank you for your reply.

Apparently, my question is incomplete.

I came across the below examples on Macmillan Dictionary. My question is: Why isn't the same preposition used in both sentences, as to my knowledge, saying "my uncle from my father's side" is incorrect and "on" should be used instead.

Ecample sentences on Macmillan Dictionary:

Which side of the family is his uncle from?

on someone’s mother’s/father’s side:

Rose is my cousin on my mother ’s side.

Thank you!

The context (verb, interrogative pronoun) governs the proposition;

get... from

I get my good looks from my mother / my mother's side of the family.

is .. on

Rose is my cousin on my mother’s side. (On = position on a family tree)