Given the fact that Peter and the apostles are speaking to a crowd gathered around them either in the street or in the upper room, it is unlikely that they had an audience of 3,000 people. A crowd of 50, 100, or even 200 is more likely. If this was the reality, then the apostles spoke to several smaller groups of people over the course of the day(s). (It is possible that the baptisms took place over a longer period and not all of them at once on the day of Pentecost.) The apostles did so not only at their present location but also at the pools where the people were baptized. Though only Jewish men were expected in Jerusalem for Pentecost (Exodus 34:23, Deuteronomy 16:16), nothing prevented them from travelling with their families (e.g. 1 Samuel 1:1–5). It is thus very possible that a smaller crowd of people, having been persuaded by Peter and the apostles, went home, gathered their friends and family, and then went to the washing pools to be baptized. The baptisms would then have included men, women, and children, consistent with household baptisms seen elsewhere in Acts (see Acts 16:15, Acts 16:33).
41 So those who received his word were baptized, and there were added that day about three thousand souls.