What's the right word for "wife"?

In the Japanese short story I am currently translating with enormous help from my conversation partner, I bumped on the word for "wife."

A bride and groom at Meiji Shrine in Tokyo

In the story, the protagonist is introducing his bride of less than six months to his grandmother. He says, ぼくのお嫁さん ("Boku no oyomesan") "[This is] my wife."

I bumped on "oyomesan" because it sounded like a polite form that would be inappropriate for a younger person use to identify his wife to an older, and therefore senior, relative. For example, I've been taught that when speaking of another person's wife—"your wife"—you use "okusan" (奥さん). When you refer to your own wife—"my wife"—you use "kanai" (家内). One is polite, one is humble. One would never say, "Boku no okusan," so where does "oyomesan" fall in this continuum of politeness?

The dictionary is not a lot of help. The definitions include "a (young) wife," "bride," "daughter-in-law." It gives the expression "yome o toru" (嫁を取る) to mean "to marry; take a wife." I asked conversation partner about it.

She said that "yome," unlike "okusan" or "kanai," carries nuances of "the woman who will care for my parents, homemaker, and mother of my children." Apparently the other two words are much less freighted with meaning.

Because it has all those nuances, of course, it is impossible to translate without stopping the story. It's what makes translation impossible and, as I slog through it, so interesting.