Is ya-ya a name for grandmother?

Answer 1

No, it's a term used by Filipino children and teenagers to call their house helper/caretaker. Soon, this term became widely used in satires, television shows, etc.

Otherwise it Could be Greek, which in Greek it means Grandmother.

Answer 2

Yes, "Ya-Ya" can be a term used to refer to a grandmother in certain cultures or families, particularly in the Southern United States or in Greek families where it is derived from the Greek word for grandmother, "γιαγιά" (pronounced ya-ya).