I'm not entirely sure what point your wife is attempting to make by quoting Ro 8:18-25, but it can't be to establish that there are two classes of Christian believers, because this is certainly not being discussed here.
Chap 8 of Romans is a discussion of what True Christians call the Doctrine of Sanctification and the specific role that the Holy Spirit plays in this regard. From vs1 to about vs 25 Paul discusses the believer's bondage to sin and its attendant trait- death. Before the believer became a believer he/she was a slave to sin, and consequently walked according to the flesh, which is a path that leads to death. [vss 1-6] However through the grace of God, He has imparted to the believer the Holy Spirit, who by indwelling the believer impels him/her to walk according to the spirit and consequently to life. Unforttunately the Watchtower knows nothing about this doctrine of the In-dwelling Spirit.
When the Holy Spirit thus dwells in the believer [vs 11] He brings about the miraculous work of redefining the believer according to the ways of the Spirit and not the flesh. This in turn leads to the believer being adopted as a "Son Of God" and like any child who is privileged to inherit the estate of the parent, the believer becomes an heir of God and fellow heir of Christ. [vs 17]
Now in all this section there is only one "class" of believer mentioned. This "class" is referred to in the first person plural personal pronoun: "us" or "we". The Christian believer cannot read this section, as Watchtower followers do, and apply the third person pronoun: "they" "them" to the text. Either you read it and believe, or you don't read it. But to read it and apply it opportunistically, and selectively, simply because of a precognitive requirement of Watchtower theology is to make a mockery of the Word of God. Having constantly being fed on the monotonous and propagandizing literature of the Watchtower, the Watchtower follower has this remarkable ability to apportion sections of scripture to make it apply as and when it aligns with Watchtower theology. Ultimately that is the epitome of Watchtower success in brainwashing.
For instance the Watchtower follower will read vs 12 which says: "We are under obligation not to live in accord with the flesh" and the "we" bit refers to the individual Watchtower follower, but mystically, this "we" by some arcane mutation, transmutes into "them" just three vss further. Thus a dichotomy is strained out of the text and forced into a preconceived mould to prop up Watchtower theology.
We now come to vss 18-25. For reasons that Paul does not specify, not just humanity and the terrestrial abode we all inhabit, but all the physical universe became enmeshed in this decline into decay and corruption, with the whole "creation" being subject to "futility" not of its own accord, but simply because God subjected it to this dissolution. Thus slowly, not just all humanity, but all creation is dying, and slowly running down.
The expression in vs 19, "eager expectation" [NW "T"] "anxious longing" [NASB] is from the Greek "apek-dech-omai" and is used seven times in the NT and every time refers to Christ's Coming Again [Ro 8:19, 23,25, 1Cor 1:7, Gal 5:5, Phil 3:20, and Heb 9:28]. Thus,"we" the regenerated [born again] sons of God, will be "revealed" when Christ returns for His own. "We" will share His glory, but always as inferiors, and all creation will be restored to its pristine glory as originally envisioned by God. All hope then, not just for "us" but all physical creation, rests not in some "kingdom" or the "vindication of Yahweh's name" but in Christ coming again. Physically, tangibly, corporeally, and personally.
As can be seen then there is only two classes mentioned in Ro 8:
1 "We" who are sanctified by the Holy Spirit and made "sons of God" by adoption. [8:16]
2 Those who are in the flesh. These ones cannot please God. [8:8]
Unfortunately for Watchtower followers there is NO third group. Those who are in the flesh, but who because they prostate themselves before the "spirit-directed" organization, can please God.