"Nonstandard forms of English imply close relationships and family values" best summarizes the central idea of the excerpt.
The narrator describes the customized version of English she uses with her mother and how she has developed a derivative of it with her husband over time ("over the twenty years we’ve been together I’ve often used that same kind of English with him").
You could call it "nonstandard" because it may appear as grammatically incorrect to native English speakers ("Not waste money that way").
This nonstandard form of English is closely linked to family relationships because we are told that it is "the language [the narrator] grew up with," her "family talk." Moreover, from this family talk, she developed a "language of intimacy" with her husband, who we can guess is a native English speaker used to hearing her speak that way.
