Communion and Nursery Workers

This is a fairly difficult question because the Bible really doesn't tell us very much about the way the Lord's Supper was observed in the early church, or even about the nature of the meetings of the early church. It does seem that the Lord's Supper was a communal meal in which everyone was to participate (1 Cor. 11:20ff.), but it also seems that this communal meal was to be enjoyed when the church "came together" (1 Cor. 11:17ff.). In other words, it looks like everybody in the visible church partook (here I differ from traditional views of 1 Cor. 11:17ff. that understand Paul to have been fencing the table; see my treatment of that passage in another answer), and that the whole visible church was present. There just doesn't seem to be any evidence that the early church left its children and nursery workers, or anyone else for that matter, in another room. Basically, by dividing our congregations in the way we do, our modern churches have created a scenario that did not exist in the early church, making it difficult to know how to apply Scripture consistently to our practices as the gathered body of Christ.

You are correct that most Reformed theologians have historically required people to examine themselves, per Paul's insistence on personal examination in 1 Corinthians 11:27-29. As I have written elsewhere, I think this is a flawed interpretation of these verses, but this has been and continues to be the mainstream Reformed view. In any event, the question as to whether or not the nursery workers have been given the opportunity to examine themselves is open to debate. Certainly the opportunity exists for them to do so, whether or not they are present to hear an exhortation to do so. If they understand that they are supposed to examine themselves first, most adults are perfectly capable of doing this with or without the audible reminder. And probably most nursery workers have heard the words of institution enough times to remember them without hearing them, so that they still grasp the significance of the elements (much as the people who are present for the proclamation of the words of institution, but who are not paying attention when they are spoken because they are distracted by their children, or playing the background music, or whatever).

If in our analysis of our modern meetings we determine that nursery workers are not participating in the corporate gathering of the church, then we will tend to avoid including them in the sacrament, just as we would avoid giving private communion (on the basis that it is to be a corporate event). If instead we determine that they are participating in the corporate gathering of the church, despite the fact that they are in another room, then we will tend to include them. It seems to me that an argument can be made either way, depending on how one defines a "church gathering" (as opposed to a "worship service," since the Bible explains the Supper as taking place in a "gathering").

Now for the really difficult stuff: In questionable matters such as this, where Scripture is not altogether clear, we have at least some obligation to tolerate a variety of views. It is inappropriate, in my view, to be more dogmatic on this subject than the Bible is. At the same time, we also have an obligation to submit to our church leaders (Heb. 13:17). If the church leadership, which would be the session of your PCA church, has determined that including nursery workers is appropriate, and if you conclude differently, it is important for the sake of church unity and for the sake of obedience to God that you submit to their ruling until you can get them to change it (by appropriate means, not by contention, etc.). At the same time, you should not violate your conscience (e.g. if you are a nursery worker and don't believe it appropriate for nursery workers to partake, you should not partake while working in the nursery). To complicate matters further, the PCA Book of Church Order - which is part of the "constitution" of the PCA - allows the minister to "invite those who have been approved by the Session, after having given indication of their desire to participate" (PCA BCO 58-4), arguably giving the session the authority to invite nursery workers to participate. Then there is the whole issue of "private communion," which some branches of the Reformed tradition practice while others do not (the PCA BCO does not address this issue explicitly, perhaps in order to leave it to the individual sessions to determine). If a church accepts the idea of private communion, certainly nursery workers could be covered under this umbrella if the elements are presented to them along with the words of institution, etc. In some PCA churches, the format of congregational communion is that the elders repeat the words of institution to each communicant, and this format might also be used to include nursery workers.