I can't believe this yue woman didn't realize she was in love with mina back then and now one of the reason her daughter fell in love with her past best friend is because she doesn't shut the fuck up about her.
I wouldn't think it too strange she revered a girl she knew in high school - at least when talking about the type of person you want your kid to be. Would probably be strange in other topics, but given that they drifted apart after high school and the husband may have only seen Mina at their wedding, if Yae hasn't made many friends since then, it wouldn't even blip on a radar that she talks about her old best friend.