Probably the person "studying the Bible(tm)" with your wife has access to the local Kingdom Hall Library. Nothing beats seeing this stuff in black and white. If she does not have access to the Kingdom Hall Library, she may have a copy of the official Watchtower CDROM, which contains recent Watchtower publications in a cheapo "text only" format.
Here is where you can show your wife that JESUS IS MEDIATOR ONLY FOR ANOINTED, not for her:
THE WATCHTOWER April 1,1979 page 31 "Questions from Readers"
Questions from Readers
? Is Jesus the "mediator" only for anointed Christians?
The term "mediator" occurs just six times in the Christian Greek Scriptures and Scripturally is always used regarding a formal covenant.
Moses was the "mediator" of the Law covenant made between God and the nation of Israel. (Gal. 3:19, 20) Christ, though, is the "mediator of a new covenant" between Jehovah and spiritual Israel, the "Israel of God" that will serve as kings and priests in heaven with Jesus. (Heb. 8:6; 9:15; 12:24; Gal. 6:16) At a time when God was selecting those to be taken into that new covenant, the apostle Paul wrote that Christ was the "one mediator between God and men." (1 Tim. 2:5) Reasonably Paul was here using the word "mediator" in the same way he did the other five times, which occurred before the writing of 1 Timothy 2:5, referring to those then being taken into the new covenant for which Christ is "mediator." So in this strict Biblical sense Jesus is the "mediator" only for anointed Christians.
The new covenant will terminate with the glorification of the remnant who are today in that covenant mediated by Christ. The "great crowd" of "other sheep" that is forming today is not in that new covenant. However, by their associating with the "little flock" of those yet in that covenant they come under benefits that flow from that new covenant. During the millennium Jesus Christ will be their king, high priest and judge. For more detailed information, see Aid to Bible Understanding, pages 1129 and 1130 under "Mediator"; also God's "Eternal Purpose" Now Triumphing for Man's Good, page 160, paragraph 10; also The Watchtower issues of February 15, 1966, pages 105 through 123; November 15, 1972, pages 685 and 686, under the subheading "Leading the Way to a New Covenant"; and April 1, 1973, pages 198 and 199, under the subheading "The New Covenant."