Rin probably learned from Kaede how to interact as a mother with that hug thing, as I doubt her home village taught her and she was likely orphaned years before she’d fully understand such nuances from her mother.
I don't think its down to one person though definitely Kaede would have told her. Its more like the general culture Rin grew up with. She might have also learned from Sango since she also came from a warrior class.





















