I have to say that I’ve often seen the EMHCs enter in the procession but that that is usually when they sit in the sanctuary with the readers and altar servers; I haven’t usually seen it when they come from the assembly to exercise their ministry. From the GIRM I see nothing wrong with the practice. In my own parish, we only process the with the Cross bearer, candle bearers, the reader with the Book, and the priest. Unless of course we are having a baptism or wedding as written in the Rite in which case the parents, godparents, child(ren) or bride, groom & witnesses are also in the entrance procession.
I’ve been in your wife’s position at least once. A major decision was made that folks in our parish would no longer stand for the Offertory Procession (why they were doing it in the first place was unclear), no longer kneel during the EP (because someone convinced the Pastor that this was no longer done

), and no more kneeling after the Agnus Dei. The Pastor instructed me to put the announcement in the first Parish Bulletin in the Fall.
Now, I was well aware that he avoided confrontation/controversy like the plague and I was also aware that the parish thought I was running the show – as secretary I often was blamed for things that other people had done but which I ended up being the one to announce. I quickly realized that the first bulletin of the fall coincided with his holidays and knew that if I did as instructed I would take the fall for this. I bluntly told my boss that if he wanted those changes to happen he would either have to announce them himself before he left for his holidays or it would wait until he came back home because otherwise I’d be blamed. He made the announcement before he left so the reminder did go in the first bulletin. Although I had absolutely nothing to do with it, I was still blamed.
We still don’t kneel for the consecration, 4 subsequent pastors have not seen fit to change that because they don’t think it’s important. What they don’t seem to realize is that there are people who were upset by the change initially are still upset by this change but feel they have no choice but to obey the pastor and would like nothing better than to be told to kneel.
We thought it was going to change with the new GIRM, in fact it was announced, but the Sunday before the First Sunday of Advent 2011, the priest who was with us temporarily announced that there would be no such change in our parish. We were without a pastor at the time and I think the bishop wanted to maintain the status quo until one was appointed. Unfortunately, the new pastor made clear to those who brought it up that he wasn’t going to change that. A handful of us still kneel for Consecration but I’m sure we’re viewed as disobedient.