I’m guessing he addresses her as Wife because her legal name is Mrs. Everett True, and it would be scandalously modern to call her Emily or Cynthia or whatever her given name was before she married.
Yeah fuuuuuck that shit. My in-laws send us mail to Mr. and Mrs. [Husband's Name] even though they know full well that 1) I kept my own name and 2) I don't use the Mrs honorific. I know it's stupid to get butthurt about two Southern boomers using such an old-fashioned style of address but it really annoys my feminist New Jerseyan ass. I have a fucking name of my own. It doesn't go away just because we tied the stupid knot.
Maybe if Mr True wore his girdle he might understand why self-lacing (and the many layers of buttoned clothing women were obligated to wear) takes so damn long.