Ruling on not addressing the husband's mother as "Ammah" (aunt) or "Khalah" (maternal aunt)

Question:
She says about herself: I got married when I was young in age, and I was unable to say to my husband's mother: "Ammah" or "Khalah." And when I grew up, I was still unable to say it, because I had not become accustomed to it from the beginning. My question, O honorable Shaykh: Is addressing the husband's mother in this way considered one of her rights, such that I would be sinful for not saying it, despite my great respect for her and my good treatment of her?

Answer:
This is not obligatory; it is merely a custom, a habit. The fact that the husband's mother is called "Khalah" or "Ammah" is a custom, and it is customary to call the father of the husband "Am" (paternal uncle) or "Khal" (maternal uncle); it is not necessary. So if you address her as "the mother of so-and-so," and a person addresses the wife's father as "the father of so-and-so" or "so-and-so," there is nothing wrong with it, and there is no blame in that. And if you address her with the known term: "O Ammah" or "O Khalah," that is good—may Allah will it—from the perspective of becoming accustomed to the known thing, and from the perspective of being considerate of feelings and ensuring that there is nothing in the hearts. Likewise, if a man says to his wife's father: "O Am" or "O Khal," that is from the perspective of being gentle and from the perspective of averting harms, so there is nothing wrong with it. Otherwise, there is no blame; because these are customs that are not necessary. And if a man says to his wife's father: "O father of so-and-so," or says to his wife's mother: "O mother of so-and-so," and does not say: "O Khalah," all of that is fine. And so it is with the wife. Yes.

The presenter: May Allah reward you with good.